Bogging down a movie with "canon" and TV show background isn't going to help. It could be said the TNG-through-to-Nemesis "universe" was being dragged down by its own canon and history. Hence, reboot with the new movie and bang, success.
Yes, Khan had a show origin "backstory," but that was explained and done with with a short little "speech" by Khan. It didn't drag the movie down.
Trying to tie in and bring in so many elements from the series is just going to appeal to hard-core fans, who aren't a big enough audience to make a movie successful.
Agreed. Nemesis had a lot of problems, but not wrapping up every little Romulan plot thread from the series was not one of them.
I mean, come on. The reunification storyline was not exactly the most exciting one of the series, and while The Defector was an excellent episode, hardly anyone remembers or cares that there was supposed to be a freakin letter delivered somewhere. Lol
I do agree it would have been awesome to see Tomalak again (or the Romulan chick from Face of the Enemy). But those wouldn't have required any explanation, and could have simply been some familiar faces for the fans to see.
They also would have made for MUCH better villains than Shinzon.