It's also funny when speedrunners discover completely new glitches and exploits.
One guy had a Quest for Glory 4 run where he ignored tons of crap and still got a perfect score. It turned out that if you just kept playing after beating it, without reloading, it rolled your previous score over, making it possible to start a new game with a "perfect" after enough runs (maybe 2 or 3).
That discovery disqualified some of his runs but it was still an amusing thing to learn. Developers back then probably just never thought it would be an issue.