These tools do not compete against the lonely programmer that writes everything from scratch they compete with the existing tooling. 5 years ago compiler generators already exist, as they did in the previous decades. That is a solved problem. People still like the handroll their parsers, not because generating wouldn't work, but because it has other benefits (maintainability, adaption, better diagnostics). Perfectly fine working code is routinely thrown away and reimplemented, because there are not enough people around anymore who know the code by heart. "The big Rewrite" is a meme for a reason.