I don't program games for the same reason I don't cut my own lawn, change my own oil, or do my own dental work.
That is, there are people who do that sort of a thing for a living. I don't. Besides it would take all the fun out of it if you knew all the intricate nuts and bolts of it. Same as making missions with mission builders. They are a lot of fun to make but not much fun to play because you are fully aware before hand what is going to happen.
But back to not doing DIY gaming....I don't cut my lawnman dentist, or mechanic much slack. I expect a first class job. They deliver or I call someone else in. Why don't I demand that of game makers...well...its simply that there isn't a whole lot of alternative choices in realistic simming. I won't play console games. Ditto for racing, fantasy, or sports PC games.