I am the kind of person who enjoys "big weird" scifi like Stanisław Lem. Stories about trying to relate to and find common ground with something so alien that the prospect of even understanding is basically hopeless. Star Trek usually doesn't do stories that, which makes sense as it often uses alien races as allegories or stand-ins for real-world human relations.
That said- I thought those early Klingons were super weird and scary because they were just so alien. It really made sense thinking about how it took a century before they could get to the events of Star Trek VI, and it made the Khittomer accords feel like so much more of an accomplishment. Like- you made a treaty with WHAT?
And just aesthetically their ships and armor looked like something out of HP Lovecraft or HR Geiger:
This is not to say I dislike how Klingons were portrayed previously, kinda like Mongols in TOS or Vikings in DS9, just that they never felt scary to me. They never felt like warriors. I was never afraid for the gallant crew of the Enterprise D (a science and exploration vessel) going into battle against Klingons. But I really enjoyed the alien-ness Disco tried to go with. Anyone else with me?
EDIT: PEOPLE I SAID WHO'S WITH ME NOT WHO ISN'T CM'ON 
They would have been fine with hair. The whole thing where everyone is bald was the point that made it look bad.
I have pictures of T'kuvma photoshopped with hair and he looks great.
Another thing I want to mention is that Gene himself never held the series up to visual continuity. When the budget got better, the sets got better and so did the makeup. It was just a natural progression of the series. I don't feel like it's a stretch to keep trying to improve on alien appearances, especially as the aesthetic for the show changes and evolves. I like the SNW bridge update. I like that it's all metal and glass and feels substantial.