Can someone explain why the hate for Sugiyama? What happened?
Short answer: Guy donates to Nationalistic groups that want to bring Japan back to it's glory days, groups that are war crime deniers, wanting to effectively push back women to more traditional roles, extremely pro-military despite outcries by many Japanese (notably older) against this, horrendously homophobic (which wasn't an entire shocker, but that came out more recently), and among other things.
While we really can't do too much about the game side (that's a huge mess, trust me, since he has a co-copyright of the series and has effectively control of the Music and Entertainment business, but I do appreciate people letting Square Enix know how they feel despite this), Sugiyama also fully controls the music, so any profits off his CDs and Concert Ticket Sales, he directly profits off of 100% of these and donates money to said groups.
Given he started restricting orchestral scores of the music in his games within the last 5-7 years, I can only assume he doesn't get too much in terms of profit there and it's why it got restricted more-so to the soundtrack and concert releases, which he does fully profit off of.
Either way, he's not a good person.