The big market for these wont be with MLB players. It's going to be amateur softball and baseball leagues. They have rules about bats but they are much more generous and not as rigorously enforced. Though what you say about the bat being round must not apply to the handle as the article says these bats are already in use by at least one MLB player.

I saw them for the first time this summer. We were in the US for a bit and I had the chance to get my son some batting instruction. (We live in Hungary and he plays little league here but it's harder to find coaches and such.) We did it with a friend and his son uses these bats. They are expensive. The wooden Axe bat he was using is around $100. And those only last so long. But anyway - when you have people dropping $300 - $500 on softball bats it's not hard to see how a company can do well selling to recreational players.