I didn't watch much of "Enterprise", but from the little I remember, one possibility for its rejection could simply be that audiences had become accustomed to the types of stories being told in "TNG", "DS9", and "Voyager". The then-new show was essentially going backwards, telling "reverse history" from before Kirk's time...and it seems many were not happy about that. My own complaint about the series is partly similar - I think it was just far too advanced, to pass for events taking place before "TOS".