Good point. I've always felt uncomfortable with the lean startup mantra "If it's not working out, pivot." If something's not working out, it could be for one of two reasons: either you're doing the wrong thing, or what you're doing needs more time and hard work, that is, you just met the schlep. Deciding which one of the two you're looking at is incredibly hard. I don't think that there are any rules. The pivoting mantra just kinda glosses over that whole problem. The best advice I could distil from it would be, "If it's not working out, don't cling to it at all cost, consider pivoting." Ok.