If it had been the same premise with a different setting and characters, I may have enjoyed it more.
That'd be completely different story, tho'...
Also it's unfair to blame people for their reactions to Tokujira. As you're aware, the author's the one at fault for failing spetacularly in making her issues believable through her backstory. You say Itsuki got away with a lot, but his circunstances and the fact that he was at least reluctant about everything helped making him more sympathetic. He's a flawed character, but in this case the author pulled it off (possibly because we follow his pov).
And if those are your feelings regarding it... I'm still not sure what was a waste of time for you, then, if not the series...