I'm not very good at explaining stuff to people like they're 5 years old. But I will give it a (small) try.
You see...there's these things called "at large" bids....and when you go so far into the season with so few games left...and are so far below the "cut off line"...it makes it virtually impossible to make the NCAA tournament.
..... higher IQ people will know there's always the Automatic qualifier. And I don't have to spell that out for them because they already know about it.