Different people have different levels of social skills. In particular, different levels of fluency or dexterity at getting people to satisfy their wants. (And of course, your dexterity varies based on context.) I think of these in four stages.
Stage 1: Paralysis.
You don't dare make the request. Or you've gotten to the point where you need the thing so badly that you're too overwhelmed to communicate clearly at all. You may not even be consciously aware that you need the thing, you're just suffering for the lack of it.
Stage 2: Rude request.
You make it clear that you want something, but you express it inappropriately. You come across as boorish, pushy, childish, or desperate.
Stage 3: Polite request.
You express your desire calmly, pleasantly, and in an appropriate context. You come across as reasonable and respectful.
Stage 4: Automatic abundance.
You don't even have to ask. Either through luck, planning, subtly guiding the social situation, or very high status, you automatically get what you desire without ever having to make it explicitly known.
For example, let's say you're exhausted; you want to excuse yourself from the group and take a nap.
In stage 1, you don't dare ask. Or you don't understand why you feel shitty, you don't recognize it as fatigue. You just get more and more upset until you collapse in a heap. In stage 2, you rudely interrupt people in the middle of something important and announce that you're tired and you're leaving. In stage 3, you find a convenient moment, apologize for cutting things short, but explain that you've got to get some rest. In stage 4, you manage to subtly wrap things up so you can get some rest, without making anyone feel rushed.
Or let's say you're a straight man and you want to have sex. Stage 1 are the people who seem, to their friends, to be utterly sexless; they never show romantic interest in anyone. They're cripplingly shy. They may not even be aware that the reason they feel lousy is that they're psychologically damaged from want of a sex life. Stage 2 are the boors, the people who tell dirty jokes and hit on girls crudely or awkwardly. The lower end of Stage 2 is the madman shouting 'Voglio una donna!" in Amarcord. The upper end is, say, the sleazier type of PUA. Stage 3 are the men who ask "Would you like to go for coffee sometime?" They're reasonable, or even charming, romantic prospects. And Stage 4 are the rockstars or politicians who have women throwing themselves at them. They don't even have to ask.
The first thing to note is that Stage 1 and Stage 4 are mostly invisible and not talked about. When people talk about communication and needs, we contrast communicating inappropriately (Stage 2) with communicating appropriately (Stage 3). Advice about social skills is always "Be Stage 3, not Stage 2." Which is fine, as far as it goes. Stage 3 really is better than Stage 2. It's more considerate, more empathetic. And it works better.
But sometimes Stage 2 is better than Stage 1. The person who can only ask rudely is often perceived as having worse social skills, worse manners, than the person who can't ask at all. But the stage 1 person is paralyzed, not polite. Her 'social skills' only go as far as acquiescence. She can't use them to steer.
The mild-mannered people-pleaser may only be "likable" as long as she isn't challenging anybody; the blunt jerk may actually be more persuasive in a tough negotiation. So who really has better 'social skills'?
The second thing is that the stages relate quite directly to urgency of need. If you aren't hungry, or you know you can get food any time, you're in Stage 4. If you're getting hungry, you may interrupt your friends to ask if you can stop for lunch, putting you in Stage 3. If you're famished, you begin losing self-control and becoming pushy and demanding about food, which puts you in Stage 2. And if you're literally ill with hunger, you may lose the ability to be coherent, which puts you in Stage 1. So people who are more prone to sudden urgent needs are more likely to drop into earlier stages. (Disability blogs talk a lot about the danger of falling into Stage 1, and how rudeness is better than paralysis if those are the only choices.)
Tribal Leadership is sort of about this, in a business context. Its taxonomy is different, but the main problem the book illustrates is the phenomenon of managers who are high achievers individually, but bad at getting cooperation from co-workers. From the perspective of their subordinates, they're 'mean' or 'dictatorial' or 'bitchy.' From their own perspective, they're overworked, and saddled with an incompetent and mutinous team.
The point of the book is that such people fail to get cooperation because they're making demands. They're constantly giving instructions, making requests. The frame is "You should do X for me." Which is a Stage 2/Stage 3 behavior, and results in resistance. The goal is to get to Stage 4. To cause people to do X by making them feel it's their own idea, or part of a democratic/tribal decisionmaking process, or emerges naturally from the noble purpose of the organization. In other words, getting to the point where you subtly shape outcomes but never have to explicitly request them.
Need is ugly. "Gimme" is ugly. It causes discomfort in the people around you. Even "May I please" causes a mild degree of discomfort and a mild inclination to answer "No, you may not."
The highest-status thing is not to need, not to demand, but to be automatically given. Rich people get lots of free stuff. Iron Man doesn't ask for much. Nor does Fred Astaire.
And from a Stage 4 vantage point, all asking is unpleasantly needy and pushy. Stage 4 people have a tendency to denigrate both Stage 2 behavior and Stage 3 behavior. (In more or less the way that upper-class people see seeking money as vulgar.) Stage 3 people will protest vehemently, "Hey, I'm not Stage 2, I was polite/respectful/etc!" Which misses the point. Compared to Stage 4, even a polite request looks a little awkward, a little gauche.
Is Stage 2 necessary? Need one be rude at all? Or can you just graduate from 'inhibited' to 'respectfully assertive' without passing through a 'pushy' phase? I do think it's possible, but with the nuance that people can easily blur the line between 2 and 3 -- that is, accuse you of asking rudely because you were low-status enough to have to ask at all. You have to be willing to accept some risk of being accused of rudeness, and balance that with the good-faith attempt to not actually be rude.
But in the absence of formal standards of behavior, "rude" and "polite" will always be subjective. Only when there are some general accepted etiquette standards does it even make sense to believe "I will do my best not to be rude, but I'm not afraid of people falsely accusing me of rudeness."