The remark is rooted from variable naming and code organization mostly. I've seen a C++ codebase transferred to a java developer, and he disregarded everything from the old codebase. Didn't refactor the old code, and the new additions were done Java Style. CamelCase file/variable/function names, every class on its own file with ClassName.cpp files littered everywhere, it was a mess.

The code was math-heavy, and became completely unreadable and un-followable. He remarked "I'm a java developer, I do what I do, and as long as it works, I don't care".

That was really bad. It was a serious piece of code, in production.