Jimbog1964: but then they have been off designing pumpkin tee markers anyway
Artists and designers do that work, not the programmers. Gotta give the art-farts a months worth of work too (aside from promotional emails). To the programmers it's just another picture/sprite to reference to, and the system is already set up to handle multiple tee markers so there's nothing they need to change to implement it. You're just adding another one. It's easy.
Balls, clubs, tees etc are easy stuff, and take little to no programmer interaction to implement. Again, the artists and game architect(s) take care of that stuff.