Indeed; according to this author, the guys at Naughty Dog were "awful" (writing their own compiler) during a period where I would have killed to work with them.
Well, there really is a difference between people who are reinventing wheels for good (because they really know their shit) and people who are doing it out of ignorance.
I think it's usually fairly easy to tell which person is which. (Person is either a bullshitter you can quickly catch out, or is smart and inspiring to talk to).