Couldn't disagree more.
Manichean ToS Klingons whose sole motivation is "doing it for the evulz" is not good writing, TNG/ENT Klingons having their defined philosophy and motivations is much better.
I humbly disagree. TOS Klingons are mostly well-rounded. Kang and Kor of course. As for Trelane in a Klingon outfit and the Mod Squad guy....ehhhhh.
I love the Klingons in their first TNG appearance. (and the score for that ep) I love Martok. I wish Gowron had more layers, but he definitly has an arc. But I felt way too many post TOS Klingons were just doing a "Dorn accent imitation"