problem is - tf2 is not e-sport game. Various players have various weapons and shit - on CSGO you got only skins, in TF2 it's much more not "always the same conditions for participants".
Not without removing unlocking of weapons and shit. Otherwise you will get matches 2000hours addicts with all of shits unlocked vs fresh players with basic gear.
If they are equally skilled (with regards to what they have, so the newbie is in fact better, because of smaller equimpment), it should be ok for them to play against eachother.
I disagree with you, as I play vanilla weapons in TF2 and don't feel I'm at a disadvantage. As pvh said, the vast majority are side-grades or situational. Biggest challenge for newer players is learning the ins and outs of the various load outs and then countering them. Not the availability of weapon unlocks.
I'd kill for vanilla Tf2 though, purely to enjoy that masterful art style :]