Why do they treat the second and third gen of mustangs as if they weren't there?

What I mean is that ford example when the mustang fan page uploads pictures of mustangs they never upload second or third gen mustangs. Then when ford made a mustang trailer for the 2015 mustang they made a time lapse of how mustang evolved. They put in the 1st and 5th gen. In that one they happened to skip the fourth gen for some reason. And when you go on wikipedia to see how many mustangs they've sold they skip from the first gen to the fourth gen.

Foxbodys are very popular so the fact ford left it out has nothing to do with people treating it "like it wasn't there"

M2's on the other hand DON'T have a very big fanbase and aren't really anything special so THAT'S basically why that one might have been left out