When I made a game crash through a bug before I did not consider myself beating the game, that is why I have or had difficulties understanding. I suppose the difference is making it crash through playing as many levels, for example, as possible.
In order to get the "kill screen" on Tetris (or Pac-Man, etc) you need to play at an absolute master's level for an extended period of time
Also the Tetris player here (edit: arguably) isn't "exploiting" a bug. The game just literally hits a limitation that can only be hit via extended and nearly superhuman play
What's interesting to me is the "kill screen" in Tetris is (apparently?) at a variable point in play.
So, this was the first person to encounter the "bug" (hardware limitation). But, future players may try to hit that point faster, with a lower/higher score, or other combinations of game state to beat the game in a "better" (more interesting) way.
I think most "serious" Tetris players can get to 30 easily in a short amount of time, right? Like 15-20 minutes? It'd be hard to think of that as a legitimate "ending."
Whereas a run to level 100+ or whatever for this kill screen is a major achievement. Took people 30+ years to get there.
I don't know, though. It's all subjective. If you want to think of a hypothetical lvl 30 crash as a "kill screen" or "ending" then hey... go for it.
Some games don't have deliberately implemented "you win" screens and gameplay can in theory go forever unless the game has a bug that prevents advancing.
In a game with no human-authored intentional "win state", one reasonable definition of "beating the game" is "reaching a state that no other player is able to surpass". If the game crashes at a certain point, then reaching that crash is a viable state that fits that definition.
If it was just happening randomly and fairly commonly, I doubt anyone would care. The reason people care here is because 1) it's a game people have been playing for so long without triggering this state before, 2) the condition was known (from an AI playing, and subsequent analysis) and people had been actively chasing it and were pushing the limits on the number of levels completed at the same time.
Pushing limits in games is fun.
I've never played competitively, but I remember well my own excitement as a child whenever I managed to trigger a glitch (such as getting enough bonus lives to overflow the lives counter on Commando on C64, which was pretty simple but still was very exciting the first time it happened).
I guess that's the difference between playing a game to the end, and exploiting a game to jump to the end or crash it. The former might be considered beating the game, the latter might not.
