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 
Folks forget the klingon's made that Augment virus which then got loose in a lab breach. If they could do that to themselves on accident imagine what they'd do to themselves on purpose to try and compensate as the implications of the augment virus turn thier society upside down. There's much I don't like about Disco Klingons but the face redesign intrigued me as a potential reaction and over correction to the augment arc in ENT, and how past exchanges like that ultimately lead to federation vs klingon hostilities. Unfortunately Disco didn't capitalize on this probably cause if they start explaining things they'd ultimately have to admit they can't get away with haveing the longest heroship in canon...