I've had people chew me out for using function objects in Java, saying it's too complicated and the newest thing isn't always great. I wanted to point out that Java 8 is 6 years old now, and qsort() has been a thing for a while.
I remember when I discovered "map" and "filter" in Python around 2000 or so and everybody I showed them to at work (it was a Java shop) thought they were so difficult and abstract compared to
ArrayList result = new ArrayList();
for (int i = 0; i < input.size(); ++i) {
etc.
To them that was the "easy" way, and I was a weird kid into weird shit. I didn't make any progress with them at all trying to convince them that "map" and "filter" were simpler than iterating over an index every single time. Now everybody has forgotten that business logic used to be one for-over-index loop after another, often nested, and debugging an error often meant running through a for-loop in a debugger over and over again examining the partially constructed result at the end of each iteration trying to figure out where it went wrong. FP saved us from that, and it gets no credit. People only think of FP as the scary stuff they haven't learned yet.
