Because someone put a cool name on it. In general, I don't think it's really a recent development, but just the latest iteration of small tricks, lean libs and

Because someone put a cool name on it. In general, I don't think it's really a recent development, but just the latest iteration of small tricks, lean libs and personal hacks which always had been around. It's just that now someone put a good name on a well fleshed out lib, made good marketing and did it at the right time when it could prosper well in the community which is now fed up with the fat frameworks and swinging back to lean solutions again.