Unfortunately thanks to cases like <https://en.wikipedia.org/wiki/Tetris_Holding,_LLC_v._Xio_Int...> there doesn't have to be any direct code overlap for a game to be in violation.

> There is no being nice in the business of copyright.

Sure there is. The concept of "copyleft" is literally about using copyright to be nice.

I don't think anybody is blaming Atari for putting TTD on sale for money. Heck, I was even planning to buy it until they pulled the obnoxious stunt of removing OpenTTD.

And even that could've been okay if they actually explained what was going on, but it's all very hush hush, which does not instill trust and understanding. If they were transparent about motivations and reasoning, they'd likely catch a lot less flak for what's going on right now.