Then why did the 2009 film make nearly as much money as all four Next Gen films combined?
1) Marketing. JJ-Trek was advertised everywhere whereas Nemesis came and went with only us noticing.
2) Over-saturation of Star Trek. Dunno about USA but here in Britain TNG, DS9, VOY and ENT were constantly on television. BBC2 was flooded with Trek and Sky One may as well have been renamed "The Star Trek Channel". The audience needed to miss Star Trek until they'd pay for it.
You don't pay to go see a hooker if you've got your sexy wife at home that'll screw ya for free. You only do it if you're single and there's nothing else available.