Because movies are written for the ignorant masses, not people who actually enjoy a thought provoking well-written story...
hence some crappy action movie with Will Smith called "I, Robot" is produced claiming to be based on Asimov's work....but has no resemblence to the real work....
Even though Nimoy has signed on to be involved with the new Trek film, I really don't know who any "Fans" can buy anybody other than Shatner portraying Kirk...it's just a dumb idea...Bond fans may be able to deal with a "retelling" of the series...but people with brains, won't buy it...
If Nimoy had been involved in the LAST Trek film, it could have been great like Star Trek VI...but instead they let Brent Spiner write his own film, so he could do his own carbon copy imitation of Spock's death, with its lame plot, full of holes and inconsistancies....
Let's see...How the hell did the Romulans get a hold of a proto-type android, where the hell did it come from? And how could they even activate another Data clone without even mentioning the what happenned the LAST time one of Data's "brothers" was allowed to roam free in the universe...
No, I don't go to conventions or any silly stuff like that...I just take a lot of my interests seriously...Music, Baseball, Science-Fiction..etc....it's more interesting than the real world