They probably don't consider it because it's ridiculously stupid to make that 2 moves in a chess match, at that levels you don't usually see that type of errors or weaknesses, that's my opinion, I may be wrong but I think a checkmate is considered the same as eating the king ( but people usually just let the king at there and don't make the "eaten" move, its considered and annotated as a move, so it may "formally" count as a 3rd move
Why do many chess players (even FIDE) say the shortest game is in 3 moves, if its in 2 moves???

Most players know it's 2, and most players know that the fools mate is not the scholars mate.
If they say 3 then they might have forgotten the number, but they would be able to show you the fastest win if you asked them, even if they said it was 3.
Scholar's mate (with bishop and queen) is 4. I would assume no experienced player would show this mate and think it is the fastest.
I figured out (alone) that the shortest chess game that could be played is in 2 moves, but i know many chess players (even FIDE players with 2000 plus rating) who say the shortest game is in 3. Whoever also knows that (or figured it out now) please comment.