That`s not striclty true mate, I went to many a Rave (in the true sense of the word)\in my misguided youth, and the prodigy appeared at a few, they played 4 aces in Dalston Hackney for christs sake, it doesn`t get much more underground than that, they were seriously respected.
A) Cos they rocked the joint. Like, they REALLY rocked the joint.
B) Cos they made it, they blew up and took "our thing" the illegal rave sound into the accepted media spotlight.
The original releases were by todays standards "cheese". But Cheesy dance music didn`t really exist then. The cheeky sillyness of charlie says etc was underground, and fun for the E culture back then.
I doubt you could go to a proper rave back then and not hear a prodigy tune at least once in the early 90`s.
Liam garnered a lot of respect in that sense, he was real, he didn`t turn up making pop, he was there with his kit burning out bassbins in warehouses and fields and clubs getting mental with the rest of us.
He just made a sound that had that edge that gave it mass appeal.