I just want to add my 2 cents. Said cents being pretty much copy pasted over the years because someone always snipes someone, and my thoughts are always the same.
I really understand both sides. I've been on both sides in the past, as a former scanlator. One is a new group or solo translator who sniped a series because they were slow/delayed/whatever. The other is a group who's worked on the series for a very long time, and feels they got something stolen from them.
We're all happy when a new chapter comes out, regardless who puts in the work. And yes, it's a grey area non-licensed work anyway, so nobody has the right to dictate who should or should not work on a series. It's a free internet. I don't think I need to cover this much, everyone knows this side of the story.
But speaking about Hyakuro's side, I think some things need to be highlighted. You can't blame them for being at least slightly angry. They're not just working hard to get the current chapters, out they worked hard to get them out in the past. It's hard enough doing it once or twice, to a quality level few people actually appreciate. It's even harder to keep doing it, for dozens or a hundred chapters. And there's a lot of other things they could be spending their time on if someone else is already working on a series.
What is sniped isn't really the 'right' to scanlate a series, it's unlicensed. It's the motivation. And it's especially demoralizing if the work isn't as good as yours, particularly if it's by a large margin. That forces you to make the unpleasant choice between giving up the series and accepting a lower quality version, done by someone of unknown motivation (because he could drop it too, and frankly, most first time scanlators drop series really fast), and working on it anyway where people don't really need it, since the truth is the vast majority of people won't even be able to tell or not care if the quality of the scan or translation is good or not.
That just could have been solved if snipers bothered to communicate with the original group. Even if to just say "I'm doing this until you get back on track" or "I'm taking this up whether you continue or not". It doesn't really matter, what's important is that a dialogue is established. When that happens, people won't be working out of unknown factors. If the group is stuck up and refuses to talk, or declares that they "own" it, then fine I can understand. Do what you want.
But otherwise, honestly, I don't get why it's so hard to reach out. It doesn't cost much to be nice, and it's not surprising to see people react badly if they get taken by surprise.
I'm not really saying anyone is wrong, since nobody owns the series. But there are things that maybe we can do to make a better community anyway.