I like all the Eeveelutions, but the one I dislike most has to be Flareon. I'm sure most of the reasons as to why it falls short of the other Eeveelutions have already been said - regarding its poor typing, movepool and stats (bar attack). Flareon's movepool and other stats just do not cater for its remarkably high Attack stat. Usually for a physical sweeper, you need speed, which is something Flareon lacks.
Most of Flareon's STAB Fire-type moves are special, especially the stronger Fire moves, such as Fire Blast and Flamethrower, while Flareon's strongest Physical STAB move is...Fire Fang. Sure, Flareon can use its new Ability, Guts, to boost the power of its physical moves, but it just...doesn't suffice.