I chose to focus in on Python since it's incredibly versatile for the kind of data analysis that I do, but I've noticed this C++ trend, too, although it seems like Solidity is a JavaScript fork. I'm guessing C++ is preferred it can handle the kind of throughput needed for processing blockchain transactions? I'm just taking a stab in the dark here, though.
I think it also has to do with security or perhaps even the insecurities (almost features) in C++ (bufferoverflows due to pointers, etc). And don't forget that C++ is a programming language so it does not need an interpreter while Python (great fan btw) does.
Time for me to pick this up again now, after reading this post. It's at least a decade ago I last finished a program in C++. But it's still my favorite. :)
Thanks @brandonh, well written and upvoted! Same goes for you, @Joshpeterson and @dan.