Part of it is to do with the quality of the composers hired. The reason the entire FF series keeps getting brought up, for instance, is because Nobuo Uematsu did the vast majority of the music for the series from I-X. And Nobuo Uematsu is to gaming what John Williams is to film. Any composer who can consistently come up with the likes of One Winged Angel, Terra's Theme, You're Not Alone, Aria di Mezzo Carattere and more is going to get namechecked a lot. The guy's a legend, and he worked on the majority of the FF series.
Same for Jeremy Soule, who's worked on a huge amount of games. His theme for the Elder Scrolls series, in all its iterations, is as majestic as any Hollywood theme, hence why the series gets brought up. Anything he works on, he tends to bring a high quality of composition to. Same for Marty O'Donnell, Yoko Shimomura, and others.
The videogame industry has a very high quality of composers working in it. Hence why so many games are brought up in these discussions. When you have people as talented as Uematsu, Shomomura, O'Donnell, Soule, Harry Williams, Koji Konda, etc, etc all working in the same industry, that's a huge amount of games with a stupendous amount of musical talent involved.
And there's so little that's widely acknowledged as bad.
Unlike being in a band or a pop music group, becoming a VG composer generally requires having qualifications. If you want to compose VG music, then unless you're Nobuo Uematsu, you're probably going to have to study music to a degree level at a dedicated music college. This tends to raise the quality a lot. Once you start studying music and learning how it's put together, it becomes a lot easier to avoid the pitfalls that many bands and artists fall into. In short, even if it takes a lot of skill to compose 'great' music, it's very easy to avoid composing 'terrible' music once you've learned about theory and composition. This is the case for the majority of composers in the industry, hence why there aren't many games with truly 'bad' music.
