My own guess (as much as its worth) would be that 90% of those people who rated the movie < C or those that rated it F before seeing it would not be TOS fans (worried that the movie was not faithful to TOS).
I dunno. If you check out the Facebook page for the "Phase II" fanfilms, there are a number of very angry anti-JJ TOS-only fans there. But how representative of the wider world are any groups of online fans? Perhaps not very.
And again, most fans who dislike Bad Robot's ST efforts seemed to have been down on them from the moment that JJ was announced as the new custodian of the movie franchise.