(I don't really know any of the new Pokémon's names, sorry for that.)
-The fire starter. Really, do we need another Fire-starter with scratch? Do we need another Fire/Fighting-starter after we've had Blaziken?
-The other two starters aren't really impressive either. A Grass/Ground combination nullifies the Grass resistance for Water and a fire Pokémon stands a chance against a Steel/Water Pokémon, much like he could handle a Ice/Water Pokémon. Either way, Infernape is the best starter due to it's type combination and once again Grass is the weakest.
-All the new Pokémon, except for the Luxray-line, are buttugly.
-Way too many legendaries.
-I hate the new evolutions or babies of older Pokémon. Who wanted a new Eevee-evolution, really?
-GTS didn't quite work well. What's the use of only being able to find Pokémon you've seen?
-Characters aren't fun anymore. It gets old, really.
-Character design also isn't cool anymore.
-We have 400+ Pokémon, and yet I still have to run into Geodude's?
Really, I wish Nintendo would just delete this generation from the Pokémon... database, whatever.