If you are talking about my friend. He doesn't plan to get rid of his old Amiga for exactly that reason. He just wants to be able to move on, have an upgrade route. He prefers the familiar way the A1 works over Mac/PC.
I can't remember his exact reasons, but they seemed perfectly sound.
His may be a more unique situation since he writes/ports stuff. I guess a normal user would be more limited. But familiarity is a strong tie for some people.