You do ask about the more difficult characters for me to write about 😛 (Kidding, you’re more than welcome to; I like your questions!) 

It’s very rare for me to actively dislike a character in Tokyo Ghoul, and I’d say the only three I dislike are Kaneki’s aunt, Mutsuki’s father, and Mutsuki’s mother (there’s no excuse for letting your child suffer like that, sorry not sorry). I guess I’m also not a fan of Tokage. But anyways, all that to say: I don’t hate Yoshitoki either.

It’s extremely hard for a child to break out of the system in which they were raised. He probably didn’t think he had a lot of choices in his life, though actually I’d argue that’s not an excuse, but it does make me feel empathy for him. He also seemed to have good relationships with Haise and of course Marude, and seemed to respect them beyond merely wanting just to use them as tools, but the Washuu were still running a major system of dehumanization and abuse in the Garden (I know they’re ghouls but for the sake of linguistic simplicity I’m just going to use common terms). 

Yoshitoki may have been kind in some ways, but he was running a machine of hypocritical evil and didn’t seem as if he was genuinely interested in questioning it, or in wishing he could break out of it. Essentially Yoshitoki’s life was tragic: he never really had much of a chance. None of the Washuu children did, but they still chose to perpetuate this system.

I’m curious to see whether Marude ever mentions what happened during their fight, as I’ve seen speculation that Yoshitoki perhaps took his own life. I’m also curious to find out why exactly it is Marude wants to do when he takes over the CCG–is he still operating under the assumption all ghouls are evil and they need to return to what had been the status quo for so many years? If so then why is he working with Matsuri? (And possibly Hide since we don’t know whether he’s a ghoul or a human.) Lots of questions there… 

Sorry this might not be the best answer. Thank you for the ask!