User blog comment:Gundam Legilis/Animated Goodness/@comment-28288412-20160605012137/@comment-24573226-20160605231714

The primary reason isn't because they lost profits, the reason is because someone changed and stamped their art and story without permission.

Think just domestically. Images are so accessible on the internet now. Ever known an artist who had his or her art stolen, manipulated, and then credit taken by someone else? Someone else's watermark slapped on it? It's awful.

Noted: at least scanlations aren't trying to claim the mangaka isn't the artist. But some do try sketchy stuff like putting their own mark over it and asking for donations for their time and effort, when the whole thing was illegal to begin with. A fan should give the money to the mangaka.