Mostly, it boils down to selfishness and "laziness". (Although I try to be very careful about that term, because I do not believe in it as generally used. I use it here to define: an unwillingness to plan ahead and to have to learn something new. Not applied as a global personality trait but only used in context.)

These days you get loads of people without CS degrees that spend their days as python/js "coders" for things that don't really matter.