There's probably tons of games that have a variety of inefficient code just due to lack of developer experience. It's not necessarily visible to the user in anything but "this game eats more CPU" and we tend to have ample amounts of that.
Also worth remembering that Unity was "guilty" of this too in the past. The garbage collection would cause huge frame spikes. This wasn't something they were up-front about and programmers had to work around it. If they weren't aware, it would cause huge issues later on down the line when trying to run the games on anything less powerful than a PC.
You're right though, once things get a spotlight shone on them they often get fixed.