I think the Golf Course is up there with the Kurgan and the Nubian Pyramids as the unholy trinity of terrible improvements, for multiple reasons:
1. 2 Gold per city is a paltry amount at the end of Renaissance. I am not even sure if I want 2 Gold per city in Classical. (Up to) 2 Culture per city, again, is also terrible. The yields are literally just there to make the tile look less empty, but they don't serve any real purpose. And no, these yields don't scale at all. The only thing Golf Course gets from tech/civic advancement is 1 Housing at the end of Information Era, which to me is like a slap to the face to cap off how trivial an improvement can be.
2. The civic requirement of this improvement is so bad. Naturally a civ with 0 religious tendency can ignore the 3 bottom leaf civics, Scotland cannot. They have to spend Culture to unlock not 1, not 2, but all 3 civics to unlock their improvement, and the improvement itself is so underwhelming.
3. After the Amenity threshold change, Happy and Ecstatic thresholds were raised by 2, Golf Course's Amenity went from 1 to 2 (raised by 1), so they somehow managed to make a bottom tier improvement even less efficient than it is.
This improvement literally just gets put down to get the Amenities out, and that is it, which is back to my first comment "Scotland is a terribly designed civ with 1 strong bonus and everything else revolves around it." I don't think anyone cares about the Golf Course's yields.