I think for most people speedrunning comes as a result of liking the game in the first place, so I've never understood comments about them not enjoying the games. Sure, there are some who speedrun meme games or a butt load of games back to back, but I think even that requires at least some interest. Because why would you dedicate so much time and effort to something you don't even care about?
When I was in my speedrunning phaze, I chose games that I really cared about as a kid. My first was Soul of the Samurai since its pretty short and it was too hard for me back in the day, so I wanted to master it in spite of that. But in the end I stopped running it due to a very inconsistent enemy AI, which could make or break a run. Though at least I came up with a new strat for one of the bosses, which I'm still kinda proud of.
Eventually I learned to speedrun Silent Hill 1, which is one of my favorite games of all time. Even though, again, I couldn't play it as a kid because it scared the crap out of me. It was fun memorizing routs, learning the famous "romper skip" and actually finish runs without messing up. But, once my muscle memory was trained and I could do most of the process on autopilot, I started losing interest. I guess I like learning and using my knowledge in practice much more than chasing numbers and leaderboards.
Overall it was a cool moment in my life, where I wondered if I can do something like that, learned to do it and discovered some new things about myself. And yeah, I watch GDQ here and there if our schedules line up. Which rarely happens due to different time zones.