The original "Mad Max" gets better on repeated viewings, as the simplistic approach grows on you. It's a tight little movie, but its hard not to be initially disappointed, because of the hype, most of which I believe is derived from the sequel which is an absolute action masterpiece. I sometimes think people just jumble the two together when remembering the original.
The original is very quiet for the most part, and driven by the characters more than anything, and if you go in expecting "MAD FUCKING MAX!!!", you're going to be disappointed. It's still a very good movie, that accomplished so much on a shoestring budget.
I do sympathize with the OP though, as I too was disappointed with it, and swore it off for years after my initial viewing, thinking it was this overrated, boring piece of shit. I've softened my stance over the years though.