If you're playing for score (which doesn't mean much in SMB, but it's there if you want to), you'd want to play through all the levels. Or if you want to get m

If you're playing for score (which doesn't mean much in SMB, but it's there if you want to), you'd want to play through all the levels. Or if you want to get more lives for the later levels, you might want to play through easier early levels to stock up. It's not exactly disincentives for warping, it's incentives for not-warping.