I never had a problem with Klingon episodes. (My wife, however, does not like them.)
Maybe the writers hit a few mental blocks, and decided to... Kling-on to a race that was already there.
(I know that kind of pun has been done to death. Even with a bat'leth. But I couldn't resist.)
If you were on board a Romulan ship, you'd probably face execution for that pun :-P
The problems I came to have with Klingon episodes is that over time they became overused in 90s Trek and in comparison to their behaviour in TOS, the movies and early TNG they became almost this cartoonish caricature of rowdy space bikers. Like to the point were sometimes you had to wonder how their society could even function.
And of course there was the tendency of most characters to just roll over and accept every rude or threatening behaviour from Klingons because "we must respect their culture!" Or even worse, all those characters who fanboied/fangirled Klingon culture as if we were meant to believe it's the best thing in the Alpha Quadrant, if not the galaxy.
And then they threw in nonsense like "Klingon love poetry is considered the best in the known universe!" (you know that typical 90s humour)
Yeah I can imagine it, whole poems about skinning people alive to see your beloved smile or stuff like that
