While it was a bad idea for NoA to think SMB: The Lost Levels was too hard for us American (and Canadians, oh Canada! XD), was bringing SMB2 over a bad idea? No, it wasn't. SMB3 improved alot of the ideas that SMB2 had (holding items is the biggest one I can think of, and level warps) and it set the ground for the SMB cartoon, but other 2-D Mario games are better then Mario 2.
And if I remember correctly, Matt from X-Entertainment (it's not that kind of site, I'm not ready to get banned yet) wrote on article on SMB2. At least, I think he did, but I can't be too sure.