It's only misconception if you assume Trekkies and filmgoers alike are a hive mind. We are not.
People have different opinions and different tastes. There's no stone tablets that say "and lo, the Great Bird looked upon the Trekkies and said 'thy shall view 5 awesome movies and 5 crap movies, and one which be-eth contended'. And it was good".
Didn't happen. Some people think Final Frontier rocked, some people think Wrath of Khan was a pile of dogshit.
More power to 'em.