The issue is much bigger than people hating on Charizard fans. It has to do with a much wider variety of pokémon that have little to no competitive viability whatsoever. Much of the hate stems from the competitive battlers who see pokémon such as Charizard to be completely useless in battles. They lash out at people who refuse to acknowledge that certain pokémon have flaws (which is a preposterous notion being that the "perfect team" does not exist) and quite often have a mindset focused on a few choice pokémon that everyone else in the competitive field uses. Hatred over other people's preferences is as big a waste of time as trying to dig a pond with a spoon.
But the perfect team does exist. Wobbuffet and any five Pokemon.