What's the Deal with Klingons?

The following is a conversation that my good friend Owen Dennis and I had the other day regarding Klingons. I felt it interesting enough to post here. Can anyone answer any of our questions? Here's the convo:

Owen

Alright this has been bothering me. I've now watched all the Star Trek movies, a number of the original series, and I'm onto season 2 of TNG. Can you explain to me why people like Klingons? People go to conventions and stuff dressed as Klingons, why is this?
Klingons are the most one dimensional species ever:

"I'm an ugly alien that wears ugly cloths and I speak a language that sounds like I'm throwing up. Also I am a warrior race so that's the only thing I care about and everything I ever do is about fighting. The End."

"How are you today?"

"I'm a Klingon so I will fight you now."

"Do you wanna watch soccer with me?"

"I'm a Klingon so I will fight you now."

They have no other desires or motivations, just fighting.
Jawas, a species we see for 10 minutes in one movie in 1977, have more to their personalities than Klingons do. Hell, Gungans have more individual characteristics than Klingons do. Klingons are boring and I groan every time they come on screen.
What is the fascination here? Why do people enjoy this species? Even more, why do people intentionally dress up as such an ugly race? Most people try to dress up to be a little more cool or sexy or something, not to become intentionally more ugly.

Me

I simply don't understand how their culture was able to evolve to the point where they have star ships if all they do is act irrationally angry all the time.

Owen

This is a good point. They get so mad I would assume they would not be able to put up with the scientific process for more than a minute before they destroyed all their experiments in a fit of rage.

Daleks are more than one dimensional purely because they realize they are one dimensional and proud of it whereas Klingons are not self aware at all and in fact are their own parodies.

Me

If, too, their culture is pretty much solely based off of battles, fighting, and general anger issues, then that must mean their society had it instilled early. Meaning, before reaching warp speed (thereby meeting intelligent life outside their own planet).

This would mean that cultures within the race itself had to have been battle-ridden throughout much of history. Are they all at peace with one another now, now that they realize there are other, more different cultures to be angry at? Or are there different subspecies that still hate each other, because obviously Klingons don't get over grudges?

Owen

True. Humans are all like "we've learned not to hate each other and we've eliminated all needs and wants" but klingons are like the opposite of that and they seem to like to be the opposite of that? They must still hate each other seeing as how they hate everything.

Yes, this is the type of stuff that my friends and I sometimes talk about.
What you gonna do about it?