He may have been worried he’d find out they weren’t actually friends, but just co-workers. They take off doing whatever and he’s left in the same spot, just with a lot less money and feeling used on top of it all. He took the sure thing instead of the gamble.

I’ve had co-workers tell me if they won the lotto they would share it with me and some others. When they left the company, I never heard from them again. We weren’t real friends, we just spent 40 hours per week together and made the best of it. If this was the case with Notch’s friends at Minecraft, then they either leave, or they stick around under some sense of obligation. That would still change the relationship and could lead to some resentment.