Python didn't beat R because it's OO. It won because of its existing popularity (with many people learning it in their intro programming class) and the massive amounts of open source software built for it.
> People just don't have enough experience with Functional Programming to really know how awful it is
This is just anecdotal, but I've used a FP language full-time for the last two years with several other engineers and ramped others up on the codebase. It has its own challenges but it's significantly easier for me to reason about than OOP - less bugs, easier to maintain, easier to parse. I can't see myself ever willingly going back.
It might be helpful to know what problems you think FP has, if you have a significant amount of experience with it.