Well.... We have to remember Nintendo released their console in Japan first, which in this case should be the Famicom I believe.
I don't have a perfect answer on how they dealt with Lost Levels, but I heard of a couple of hard Famicom games that weren't released in America. Perhaps they are desensitized to overly difficult games? Maybe there are much harder games for the Famicom we did not offically get for the Nintendo Entertainment System due to them thinking we can't handle it?
Taken from the Wikipedia segment "Development"
(When The Lost Levels was evaluated for release outside of Japan, it was declined by Nintendo of America, which considered the game too difficult for North America.[3][11] Howard Phillips, who evaluated games for the president of Nintendo of America, felt that the game was unfairly difficult, even beyond the unofficial moniker of "Nintendo Hard" that the company's other games sometimes garnered.[10] He felt that it would not sell well in the American market.[9][10] In a 2012 interview, he said that "few games were more stymieing than Super Mario 2 on Famicom" and that "not having fun is bad when you're a company selling fun.")