I think you are missing a key tenant of Discourse which is critical you understand as a contributor. We, in particular, @codinghorror chooses defaults. That said we are a system of rainbows, if you are uneasy with the way polls are themed you should be able to theme them however you want in your forum.
Since it is quite clear core are not going to merge in your proposed design change instead focus on extensibility.
Is there anything about our HTML structure that stops you from achieving the changes you want on your forum?
(personally, I am not a fan of the changes, I find them cluttered and distracting, but also I only deal with like 1 poll a month so its not as though I have much skin in the game)