What does what someone else is doing have anything to do with it?
If it's really just for the benefit of the fandom and community, specifically so that those that have no access to the official translation can have something, then still holding your release till after the official shouldn't be a big deal. People wait for scans on lots of series all the time.
But then another group starts doing it, so suddenly one illegal bootleg version has to beat the other illegal bootleg version to market, while they both undermine the official by 4 days, so they can get more page views and make a better profit?
Cause that's the only reason.
It has a lot to do with it…Ishuhui release their Chinese scans Thursday/Friday and that undermines the process quite a bit and there's no running away from that especially when a full scanlation is already out. As much as I'd love everyone to read the official release, most of the discourse occurs when the first English version is out and when groups are willing to do JP->CHN->ENG scans where the quality obviously suffers the community deserves better. Not to mention RM is as scummy as they come with their practices...