I don't think its ever rude to just send your regrets, if you're not feeling up to it.
Provided you still pay, if that's obligatory, then you should never have to attend if you don't want to. Many people have times when they just don't feel that sociable, and if its not a frequent thing, its nothing to worry about.
Actually, you've made a commitment to the other members of your team. And etiquette would say that you should suck it up and go--that's what a commitment is.
Etiquette assumes that everyone can find a way to be sociable. Maybe not bubbly every time, but reasonably decent company. Even if you don't feel it particularly.
It may be that you don't want to--but we all end up having to do things we don't want to.
I don't think the OP has an obligation to always be at the peak. But if she goes (and she should), she should not be a lump who doesn't talk to anyone. She should fake it a little bit. She doesn't have to fake it a lot, but she shouldn't be so quiet and glum and antisocial that lots of other people notice.
People who go to a party and sit in the corner and just grunt when people come by are being rude. But their rudeness is not in *attending*; it's not "not participating in the evening." They don't have to be over the top; they just have to be mentally "in the event."
A "pained/sad/I don't wanna be here look on her face" is *not* "perfectly polite." Neutral is OK--negative is not. In fact, in ANY situation, it's not appropriate (not good etiquette) to let your emotional negatives become part of other people's lives.
So you can be quieter, but you shouldn't let *negative* vibes enter. That's your obligation to the world at large.
(The person who yelled at the OP was over the line in yelling at her or even chastising her, so I'm not willing to trust that person's judgment about how communicative or "involved" the OP was in the social event. I'd rather trust the OP's word, because she seems more reasonable. So if she says, "I was quieter than normal, but I did clap and smile, and I did answer questions when they were put to me," then I'm good with that.)
Absolutely perfect analysis and advice (as usual) from Toots.
Your bowling night is BOTH a team commitment AND a social event. So you are correct to show up even when you don't feel like socializing (assuming otherwise you are letting your team down). But because it is also a social event (not all bowling leagues are, I'm sure, but clearly your team considers it so), you do have a social obligation to be a good social participant, too, even when you don't feel like it. As Toots says, you don't have to be the life of the party (ever). But you do have to hold up your end so as not to put a damper on things for everyone else. Their very exuberant behavior seems to be the convention for this team, and they have a right to expect it. It's not like you are out for your monthly quiet dinner with your closest friends. That's what this team is like. When you participate in an activity, you participate, and the activity here isn't simply "bowling," it's "bowling and socializing."
Maybe you are just on the wrong team. But there you are. So although I think you are fine with doing the minimum, socially, I do think that it sounds like that the minimum in this very enthusiastic group is more than just sitting quietly and not being gloomy; even if it's not to the point where you're bumming people out, sitting with quiet dignity is likely to make the rest of them feel self-conscious and childish. Of course sitting quietly isn't an inherently rude act! And the "find an ally" and "heads up; I'm in full introvert mode tonight" suggestions are in themselves polite. But if you're going to go to a paintball game, you don't refuse to get dirty.
If someone questions you, I agree that "I'm just feeling kinda mellow tonight" is a lot better choice than saying you don't feel sociable or aren't in the mood to be silly. That can make them feel like it's a rejection of them, and/or a judgment on their immature behavior.
Better not to let it get to that point. Even though it may take a little extra push from yourself some days, make the effort. You can do it. It's a useful social skill to develop.
Don't be so sure you're the only one doing it, either. After all, how sure are you that not a single one of your jumping, cheering teammates isn't feeling something else inside? (They may even have looked forward to this night to be silly and forget their troubles for a bit.)