I personally hate how Klingons were depicted TNG+. Buncha unbathed Space Vikings so pathologically stupid that it breaks suspension of disbelief that these morons ever managed to evolve beyond the Stone Age, let alone develop FTL travel and build an interstellar empire.
This is the correct opinion. I wish they stayed like they were in the movies. The Undiscovered Country even showed an intellectual side of the Klingon people that I don’t think was ever explored in any of the TV series afterwards.
Not just Klingon culture though, in particular Worf as a character became worse the longer he existed. At the start of TNG, Worf claims that Klingon culture is completely alien to him, having been raised by humans. I’m not sure how early it started, but at some point the writers decided to make it Worf’s one goal in life to be the most Klingon a Klingon could be. This caused more and more episodes to be fully dedicated to developing Worf’s Klingon ancestry.
Also the bat’leth is stupid. It’s one of the most impractical weapons I’ve ever seen. The knife from The Search For Spock is a much better melee weapon for Klingon warriors.