FRP is not only for as you put it “ event streams or this massive amount of side effects”. Its for everyday coding too, like simply handling events, or basic gestures- like drag and drop.
You do realize you just said “It’s not only to handle event streams, but also everyday coding such as handling events, and handling lots of related events”, hehe ;)
I like to see it as part of the toolbox, but not as THE toolbox.
For now, it’s just not nearly as big as some other stuff. When you think about it, even React itself, while growing quickly, doesn’t even have close to the majority mindshare. It’s a subset. Even if you combine all of the other new tools, reactive stuff is just a subset of a subset of a segment of the community. A little too small for now, even if its great. If I just wanted to point out “Great things a few people uses”, I’d have put Elm at the top of my list, not React/Babel.