Ever get the "I told you so" feeling in your work? I'm really feeling this way about the resurgence in popularity of functional programming in the software dev world. In a few words, old school programming is making a huge comeback, and supplanting object-oriented code as the king of the hill. It's kind of a weird thing to watch from the position of someone who does professional development, but who is not a formally trained developer. Essentially, people waaaay over-applied OO to everything, and ruined the very idea of OO programming. There's nothing inherently wrong with OO, it's just a case of everything looking like a nail for decades now. Commercial code has these massive hierarchies that are impossible to interpret, and objects don't act like, well, objects. They were supposed to be little boxes that internalized their workings and talked to each other in a predictable way. Except people thought inheritance was some kind of godsend that they applied for everything. Just because you're building a Cat, that doesn't mean you need to inherit from NoahsArk(). And it never meant that everything Cats do needs to be inside the Cat object. All the big names like Sutter kept trying to discourage people from coding like this, but no one listened....
Anyway, the frustration with all of this + the need for concurrency means good old fashioned programming with self-contained functions--which is probably the first thing everyone learned how to do--is coming back. It's already going stupid, though. You've got proselytizers preaching that all should be functions and lambda is life. That's just as stupid. OO still has its place. I suspect we are at the far edge of a pendulum swing that will hopefully end up with people coding the way the old gurus said we should've all along...objects acting like objects, but interacting through functions. I think a lot of people didn't like that paradigm for its asymmetry. People are offended by the mix of Cat.eat() and play_together(Cat cat1, Cat cat2), but it is logical.
Sorry for the rant that most people don't care about, but I needed to hash that out somewhere.