Easier to use than typing something like:

  Here is an equation: $y = x^{2x + 1}$.

Probably not. GUIs trade learning for speed. You never have to learn anything, but you'll never be fast. The GUI will always be in your way, slowing down your work. TeX is the opposite -- you have to read a lot to get started, but then the only difficult or tedious part of writing will be the subject matter you're writing about. The only barrier between your mind and beautiful output will be your slow fingers :)

LyX and Texmacs are a good compromise, however. You can write the code when you're comfortable doing so, but you can click stuff when you're learning.

Weird. I haven't had a college professor who has to typeset mathematical equations who doesn't know LaTeX.

Perhaps he could have said "It's easier to get your students to upgrade to Word 2007 than to use LaTeX".

Which would be true. However, it's a much better idea to get them to use LaTeX.