Well, you can style it with css. You just need to override their !important rules with your own !important rules, and make sure to use more specific cascade selectors so that they will take precedence (since twitter’s styles are added to the DOM after your own page css).
Unfortunately, a lot of those styles are very complicated/heavy, so it’s not going to be super-simple. I’ve been playing with it to see if I can get it to play nicely at mobile widths, and so far, no dice. I think twitter is to some extent elevating the cause of consistent brand-look above ease/usability in this case.