I've been wondering how this guy was doing and said from the start that he had ZERO chance of making a living as a professional golfer. He's 5,000 hours in and just shot 89 - give it up bro. The biggest reality check should be his scrambling - he's at a self-reported 19%. Pros are usually around 55-60% and the best are over 70%.
He's done a lot worse very recently, shooting 56 over par over a 3 day tournament. (high 90's one day) Lot of good comments in this thread and a lot of bad ones. Yes there's no reason to think that just practicing will continue to make you better at golf. (It does in the short term but quickly has diminishing returns and flat lines pretty quickly).
And it's absolutely crazy to think that there aren't genes that confer advantages for all sports. "Sure genes can affect how: fast you are, tall you are, dark you are, how high you can jump, how strong you are, how smart you are, how mentally stable you are, how susceptible to disease you are, your attention span, your ability to focus, your steadiness, your ability to repeat some action, insert 1000 pages of things that genes are definitely known to affect (oh but they don't have any affect on how good you can become at some physical act?!)". Somehow that's where the unfair advantage conferred by genes ends, a magic fairness fairy steps in and says "no if someone wants to work at something they can become just as good as anyone else"
So no, there's not golf gene (just as there's no height gene) but there are a lot of genes that confer some advantages for golf just as there are for height. The height research exists, I just interviewed a guy recently that sequenced an NBA player for just that reason.