Well that's a direct effect of technology. See something once or twice you tend to say good or bad. Have unlimited access to it and now you can pick it apart and know what you want to see in a sequel or similar film. So expectations are higher before the film rolls.Plus people now are more critical of movies in general. We've become a tougher crowd.
I think the rise of high quality serialised television is a big factor, as it's created a fan culture more concerned with world-building logic, sustained characterisation, and long-term consistency. This was never an issue with TV episodes and movies that were meant to be experienced independently.
NuTrek was supposed to be an escape from that pressure, cleverly evading 45+ years of Trek backstory, but then they shot themself in the foot by having OldSpock and Kahn in the sequel.