To me it doesn't matter why Snake's retiring, just that he is.
As has been said many times throughout this thread:
1. Snake exudes 'cool' like nobody else.
2. He was one bad hombre in his hey-day.
3. He did one helluva job picking drivers once he decided to stop driving himself.
4. But most of all, he's earned everything he's ever had and I wish him nothing but happiness and relaxation in his retirement - He will be missed.
P.S. Someone said they thought Spencer was the best driver out there, and in terms of his tree savvy that may be true, but unfortunately it doesn't guarantee a ride next season. JR Todd is a damn fine shoe, and proved himself with arguably less equipment, and he's spent quite a while on the sidelines. I sincerely hope Spencer gets a ride, but there are no guarantees.