@Qwormuli It's about the time and dedication you put. Camrip/hdrip is not a bad comparison, but not great either. First, it applies only to movies, afaik (never seen a camrip tv show), which don't release as often as a manga. Also, by definition "rip" is only the quality of the video. Say, the scan itself. But not the cleaning, translating, etc.
You have a group that's putting time and effort into doing something, and then all of a sudden someone else comes to do the same thing. It's not a collaboration, not even healthy competition. They're literally doing something that's already being done. It splits the readers into the 2 groups you discuss, which means there's less returns for the group (and I don't mean money, even a thanks goes a long way, or just knowing there's people waiting for you).
Also, maybe the group picked up this manga cause it was unknown, but "if someone else is gonna do it, we might as well work on a different one". And that generates even more problems.
I'm not saying this is mature, or right or anything, but I'd say it's the general train of thought.