I think you are correct that the vast majority of games released are either mediocre or just bad. There are a lot of poorly-made games, cash-ins where most of the money was spent securing a license, or hurried games to meet a deadine like releasing at the same time as a movie or for the holiday season.
Unfortunately, this phenomenon has always been with us. The Atari VCS' glut of terrible cash-in games is what caused the console side of the industry to crash in 1983-4. There are plenty of terrible games on every system in existence, even a machine like the Neo-Geo. If you were to ask me personally, I believe the original Playstation is the worst offender in this regard (lowest percentage of good games to mediocre/bad ones).
In Memoriam RVW Jr.
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