That wouldn't work. Visa and the others don't care what exactly someone buys on Steam. They're saying that Valve can't sell certain things on their store, or they will stop processing payments that go to Steam. Doesn't matter if you pay for "points" or games directly.

The only way to get around that would be to remove the option to pay with Visa, etc. from Steam entirely and only accept other forms of payment. This would include physical Steam gift cards that could then be bought with any payment option, but only as long as Visa, etc. don't start threatening stores that sell those.

Also, to your last suggestion: I don't see how that would help. Publishers and developers need to make money somehow and if that involves Visa, etc. at all we're back to square one.