There is a card that allows you to remove oil platforms. Why bother? Unless I'm missing something in the rules, there is no reason to do so. They don't block movement, they don't move after placement, there is no direct penalty for all 12 of them being on the board at once.
It's an information that's missing in the beta rulebook, but they are blocking the path! So it can be really useful, even bring victory, to be able to destroy them at some point! Really good question you've asked there!