Some accounts are deleting their posts after a few downvotes. It’s devastating on communities like c/asklemmy.
Lemmy doesn’t track an account’s karma like reddit. So, all downvotes will be isolated to your post or comment and won’t affect your account—unless you wrote something truly horrible.
Remember lemmy is a community effort. Deleting a post also removes all comments on it. So you are not only robbing the effort others put in, you are actively removing knowledge from the fediverse. Others won’t be able to find it through search and lemmy will seem lonelier than it already is.
I think some people don’t have that sort of filter or self-moderation - they see it as their right to be offensive towards others, and would then say “they got offended”, but never “I was offensive”. Never their responsibility, always the other person’s fault.