> A cryptocurrency that scales it's size in rough proportion to its trading and thus keeps prices in check with maybe slight inflation would be interesting.

These already exist, with all kinds of incentive schemes and target inflation rates. If you're saying that deflationary Bitcoins can't possibly "win" in the long term, but something else could, I guess it's plausible and I don't know a lot about that.

I do know that Bitcoin was started partly in protest of inflationary Fed policy.