Stop being stupid, everybody. Pidgeot ex would not be broken because it would be a completely different card. Neo Genesis Slowking was a broken card, right? Well, you don't see them putting the Mind Games Poké-Power on every Slowking they make. They do NOT give every Pokémon the same moves, so don't pretend they would.
And Magikarp ex? Beldum ex? Caterpie ex? Those are even stupider. THEY DO NOT GIVE POKÉMON THAT EVOLVE EX CARDS!!!!!! Scyther and Chansey were special cases: they were both Pokémon that were created as non-evolving Pokémon, and have good enough stats that they don't need to be evolved.
Now that I've cleared up everyone's stupidity, I guess I'll answer the real question. The Pokémon that should NOT get an EX is any dumb bug Pokémon. Butterfree, Masquerain, Ninjask, Ledian, Beautifly... they're all stupid and weak. That's why I'm so upset that dumb Dustox is one of the best EXs ever made.