There are countless great games that have glitches that speedrunners take advantage of. The "any%" category of speed running is all about that. If you're saying that any game with glitches like that had bad QA and poor communication, then either
A: That is true for all games
or
B: You're holding everybody to too high a standard.
Some recent examples: There's a glitch in Zelda: Breath of the Wild where if you shield surf onto an enemy while it's taking damage while you're in slow-mo because of shooting an arrow while falling, you'll bounce off of them about a mile into the sky. In DOOM (2016), there's a physics bug that lets you rocket into the sky by standing on a railing and then... standing up. You can also glitch through doors by triggering a specific take-down animation on zombies.
Those are incredible games, and relatively bug-free.
A: That is true for all games
or
B: You're holding everybody to too high a standard.
Some recent examples: There's a glitch in Zelda: Breath of the Wild where if you shield surf onto an enemy while it's taking damage while you're in slow-mo because of shooting an arrow while falling, you'll bounce off of them about a mile into the sky. In DOOM (2016), there's a physics bug that lets you rocket into the sky by standing on a railing and then... standing up. You can also glitch through doors by triggering a specific take-down animation on zombies.
Those are incredible games, and relatively bug-free.