That's silly.
Just kidding, that's not silly and you raise good points, but I disagree on some.
DLC mess up Tournament consistency because of character disponibility, true. But as far as different game versions, I think any respectable (or non-sucky) Tournament ought to have the last version, since it's supposed to be free anyway. I think you're directing your anger at the wrong target here, consider the Sentinel nerf patch, was it directly related to Jill and Shuma's inclusion to the cast? That changed metagame like hell, to the point that Sentinel was dropped off of half the teams he was in before (which was 100%).
In the other end, you claim they do not expand the life of a game in the competitive department, but that's much more due to Capcom's general incompetence in balancing new stuff - the characters could very well be overpowered or underpowered, and ended up being the latter. Comparing it to BB scenario, Platinum is kind of used here and there, but Makoto and Valkenhayn are very popular in Tournament, so I'd say it does change the competitive scenario. Back to MVC it doesn't help that Jill was not the Jill we loved (or liked at least) and Shuma was never really popular.
DLCs that are on Disc are completely inexcusable though. And Capcom put itself in a bad spot with UMvC3, because Jill and Shuma are OBVIOUSLY in the disc now, but people have JUST bought them and would feel even more ripped-off than people who only bought the original game do. So they're keeping it as DLC even though it makes no sense whatsoever.
I don't think Capcom really cares about that though, it seems they can do whatever they want with the fanbase and get away with it...
(And I can't wait to give her more money with UMvC3 grr...)