Some do get tips and donations from readers. Some don't. But it doesn't matter anyway because
the scanlators/translators aren't selling the actual releases. Let's say ScanlatorGroupA has a Patreon and takes donations. They get $10 a month on Patreon. Say their translator gets sick and for an entire month they release nothing. Chances are their patrons are still going to give them money. Thus they are not engaging in commercial business. So it would be difficult to argue that they are operating a commercial venture on the basis of donations and if they get those donations even without releasing anything. If anyone disputes this, just point to formerly famous Youtuber "Spoony" who at one time was making thousands upon thousands of dollars a month just playing/talking about games and movies and eventually stopped releasing content yet still getting Patreon money for years on end until even his most loyal fans left.
Secondly, the original copyright holder does have some rights and leeway to derivative works, but Fair Use is exempt and protected from this. (At least for any group that could plant a legal flag in American territory, anyways. Europe has gone to shit since Article 13 and the European Union). Fair Use is often misunderstood and it is very subjective when you start dealing with actual court and legal proceedings, but many things are in the favor of the translator.
For instance,
this Fair Use Checklist to see whether what you're doing falls on Fair Use or not. Considering that translation groups aren't a commercial venture, don't necessarily get paid for the work, the work is transformative, can be a parody (those end cards with memes and stuff? ironically good precedent for transformative/parody status), and does not impact the original market of the work because... the Japanese don't speak much English and often there is absolutely no official English release.
If Japanese publishers and media groups think scanlation groups and Mangadex are making "illegal pirated manga" or some such horseshit, they need to make a few calls down to their legal department to tell them the gigantic fucking can of worms they're opening and they need to get off their lazy asses and start licensing and making this available in English. If they don't, they really don't have much right to bitch and complain. And if any Japanese company were behind DDoS attacks... Phew. That's more illegal than anything else being talked about here. That would be very, very, VERY dumb of them to do. But, sadly, some of them seem to think it's a good idea and have ties to it.
