I'm no gamer, and "bloat" has been a term used in the industry from well before "gamers" (in the sense used today) existed. It's been a term of art for over 30 years.

It also describes a very real thing.

While there are a lot of things that everyone would agree counts as "bloat", there are also areas of disagreement in the form of "one person's bloat is another's essential feature".