Oddly, I have no doubt that you would have as well. I'm sure at the time, other people would have shared your view. I know my dad did. At the time, I didn't think it was idiotic. I thought the musicianship was incredible and the performance by Gabriel was different and exciting. I had seen plenty of Grateful Dead and CSN, James Taylor, Muddy Waters Michael Bloomfield, BB King, Credence... etc.
In 1973, the only other band that electrified me like that was Bruce Springsteen, whom I had met and gotten to know a bit. The E-Street Band was still forming and David Sancious was their pianist and Ernest Carter was the drummer.
Completely different musical experience than Genesis, but electrifying none the less.
As I recall, you don't like them either.