Absolutely not. People bond because they like being around each other or because they share some goal. Making that goal a negative of "destroy X" or "protect against X" is a very clear sign that the group isn't healthy.
EDIT: Where X here means an specific group of people.
Take example of politics. The left "hates" right and vice-versa. The bond within them is tight and has been going for a long time. Whereas the moderates/centrists party will never have a future because they don't have a common enemy to hate.
I meant X on both of those as a group of people. I recon that it could have been clearer.
And yeah, there are a few exceptional cases when protecting against some other group is a very important goal. The group gathered around that goal can be even right, but I've never seen a case where it was healthy, and one should be always wary of those groups evolving into something exclusively destructive.
Okay I'll bite. Emacs and Org-Mode, these are groups that require you to do a public good with the idea that you're protecting against many X's. To do this, one can contribute in any meaningful way, big or small. For a cult, it seems to only do good, despite one of its unspoken tenets being to keep corporate interests at bay. Is that bad?
EDIT: Where X here means an specific group of people.