I just thought Yakuza was more of a chore to play than it was fun. I really wanted to like it, and I think forcing myself to do so only made me like it less.
As for the side-missions, I abandoned those mostly because of the random battles. I did not like those at all, and they are probably the main reason why I dislike the game. Either way, they weren't interesting enough to force me to go out of my way to complete them.
And this is an obvious complaint, but fuck that dub. I had to shut the door and constantly look over my shoulder to make sure no one was coming because every other word was a swear.
Also, what was up with that end battle? It felt like half of your attacks didn't connect no matter what you did. That was annoying.