The peer pressure badge awards users for deleting their own bad post.
Some users like to game the system. Just recently, I saw a post where a user posted an intentionally bad question. The user later declared that this was because they wanted the peer pressure badge.
Additionally, "peer pressure" doesn't sound particularly friendly.
Although I realise that abuse alone is not a good reason to remove something, I really don't think the peer pressure badge adds anything good to the system.
I disagree. One purpose of badges is to teach users about good actions to do on the site. While posting a bad question is, well, bad, deleting it is still good.
The number of people who post bad questions just to delete them is vanishingly small. But the number of people who don't delete because they may not have known they could or should is probably higher.
The badge almost certainly provides a net positive to the site, despite the single outlier you've found
It does add something though. It informs new users that it is both possible to delete a bad post, if they feel it is not salvageable, and it teaches them that when they can't salvage a post it's actually a good thing to delete it.
We of course don't see the benefits of this very often. They're invisible; that's the whole point. There is a lot of garbage that we aren't seeing because people learned to take it out themselves.
Yes, this does get abused in which people create garbage just so that they can get credit for picking it up. Fortunately, this doesn't happen all that often, when it does happen, at least they picked up the garbage, and finally there is only ever an incentive for this (mostly benign) abuse once per account. If users were going around creating lots and lots of trash over and over, just to later delete it, it would become disruptive. As it is, the very rare abuses simply aren't that significant or disruptive.
I would propose to rename the badge to "Nobody's perfect" or something similar. I do see the point of the badge, but the naming implies that peer pressure is a good thing, which it often isn't. It may also feel somewhat humiliating to the person who deleted their post and thus might actually prevent people from deleting bad posts. I don't think it adds to a warm and understanding culture on the site.
Another solution could be to change the action that triggers the peer pressure badge. Rather than having "Delete an answer with -3 score" which encourages deleting bad content / posting bad content because you can delete it, I would recommend changing it to become "Have an answer with a score of -3 and edit to improve it causing the score to rise to +1" (shortening that is encouraged). This new statement brings a completely different perspective -- rather than delete content (note: some content isn't salvageable), it encourages users to improve and edit their answers which I feel is what the SE sites are encouraging.
I understand that peer pressure tries to teach people how to use the site, but it is very possible that people see the wrong reason behind earning the badge -- it is not about delete anything that someone does not like, its about getting rid of content that is completely irrelevant / you posted by accident (i.e. misunderstanding a question and posting an answer that does not meet the restraints in the question; sometimes that happens, but once again, I am definitely not encouraging you to go do that).
I agree that the Peer Pressure badge has a sufficiently deleterious effect on the behaviour of some users to warrant it being removed from the system.
My understanding is that we are striving to have poor content (by community standards) remain on SE sites for as little time as possible, and preferably to reduce the chances of it being posted in the first place.
When a user deletes their own inadvertently poor post which has downvotes, the deletion nullifies them, and I think that is enough reward for them learning that they should do that.
