KaeyelThere will always be the edge case of someone not owning anything but the stock weapons, so stock weapons can not be banned at all.
Even if they were, there would have to be a gateway system of sorts before you're "allowed" to enter the lobby system, and I don't think that's a wise use of resources.
To add to this...
There could/should be a rental system for weapons deemed absolutely crucial by the community, such as the Kritzkrieg.
Or maybe make it so that you can use all unlocks in tournament mode?
I'm not really liking that the system the majority is suggesting involves special treatment for certain weapons(stock+generally liked unlocks), but allowing all weapons to be banned could be pretty horrible. Sticky Launcher would be a standard ban then, making the demoman nearly useless. That's because all the alternatives to the Sticky Launcher are awful, but maybe Valve would realize this and buff/rework the others to be somewhat useful. That could take a lot of time though, so playing demo in this matchmaking system would be terrible for a long period of time.
Also copy-pasting here what I said earlier in the other thread:
To me it seems like they're trying to make highlander more like dota and include this idea of adapting into loadouts. That's simply not possible at the moment(besides medi gun/kritz) because you cannot see which weapons a person is using unless he switches through all of them. And besides it's really hard to keep a track of all that, in addition to that you can change your loadout at any moment in time.
If they really want something like that though, it would have to be so that players have to pick their weapons at the start of the match and they are forced to use them for the entire match, similarly to how heros are picked in dota. Maybe it could evolve into picking counter-loadouts or something. That system obviously has it problems too, not being able to swap off to kritz, etc.
I don't know if that's a good idea, but I'm just throwing that out there. Maybe allow the medic switch his medigun though.