I think the Rams also have an "All-In" type attitude in their entire organization.
They hired the youngest head coach in history, they trade draft picks for top end talent, they signed players to huge contracts, they traded away their QB.
They have been kind of living on the edge and doing risky things for the past 5 years.
Something tells me they knew they could just put out a slight variation of the classic and almost perfect look -- but they didn't think going safe would fit with what their ethos is right now.
I can't stand what they did with the rebrand, especially the helmets, but I can't blame them for risking it if that was their thought process.