[codedrome]

I think the controversy and confusion about functional programming stems from the difference between procedural and OOP programming. The switch from procedural to OOP which occurred in the 1990s was basically all or nothing - with the languages of the time, mostly C++, it was a full paradigm shift.

People probably assume it's the same with FP, ie you have to do EVERYTHING as FP whereas in fact with current mainstream languages (eg JS, C#) you can just drop in bits of FP whenever you feel it is appropriate. It's a tool in the toolbox, not the entire toolbox.