But the Hubris defense is literally explained in-game. They only conceived of the Catalyst as "another tool" and were surprised when it turned on them. Even the Catalyst states that it's creators "lacked the foresight to recognize they were a part of the problem they were trying to solve." (Or something to that effect)
The Leviathans were so full of themselves that they didn't stop to think even once when they asked the Catalyst to "solve the problem" that they would be included in the calculations. They honestly believed themselves exempt because they were the head honchos in the galaxy and didn't even bother to assign any sort of operational oversight to the Catalyst. They acknowledged that the other races built synthetics to improve their lives and help them. But the Leviathans had no such need.
Also, if the thrall races were "constantly controlled" they'd never build synthetics. There's clearly an almost Prothean-esque mentality (join willingly or be enslaved) and I guess most chose the former.
Okay, except I'm questioning the legitimacy of that claim. As I said the Leviathans acknowledged that solving the organic/synthetic problem was beyond their power and created the Catalyst. Next to the statement about the galaxy bending to the Leviathans will the Leviathan Shepard meets talks about how the galaxy didn't bend to their will ("We could not protect them from themselves"). Also, somewhat apart from that, this is similar to the problem ME2 runs into with the overly apathetic/ignorant shtick with the Council and the Alliance. It's terrible characterization, in addition to all the contrivances it leads to.
Also, the Catalyst didn't solve the core of the Leviathan's problem (simply the vague conditions of it's programming, I guess). The Leviathan's didn't run the whole Catalyst plan out of love for the other races, they wanted to maintain the tribute gravy boat. And the Catalyst nuked that whole plan. I guess you could the Leviathan spouting off the thing about how they didn't make a mistake is further proof of their arrogance; however, given all the stuff I said in my first paragraph, I think that statement is something worse and 4th wall breaking.