What? All kinds of unlocks screw up other classes abilities. The basic flame thrower stops a spy's ability to disguise, a razorback his ability to stab. Airblast hinders a soilders mid-long range killing power. Etc
And for the record, I really don't understand this kind of equalizer hate. As a soilder who uses it, I switch back when a medic is in the vicinity.
And if I am using any melee weapon as soilder while a medic is healing me, I am doing something wrong.
I imagine the bulk of the hate comes from when you guys do all melee or something. Which is really something valve shouldn't be balancing the game for.