You jelly bro? Bet you you aint even close to his skillset, but anyways I'll lay it out for you since you seem like a youngster that doesn't get it. Game started being developed at around 1999 the tools for version control out there were minimal and yes a lot of things have changed since then.
You can't even imagine what kind of transition they'll need to change the DB structure to what it was in 2005 into todays DB system which should be scalable and on the cloud. Also intergrading that old engine into their bnet wow... you just cant imagine how much of a job that can be for a big dev team.
You shouldn't try to judge a very successful person, and also saying he is a shitty dev, he wansnt even a coder and he has made quite some money to not worry about working for the rest of his life.
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That person that is dismissive about Staats has no clue... just another person with a github account, programmed a small calculator for his CS course and coming off saying that translating that DB and codebase is easy and that people that originally coded wow which Staats was a designer for and not a coder are shit and dont know programming lol, funny people on the interwebz.