Because, again, learning the interface does not replace what the software cannot do. People who have both learned gimp and who need photoshop for their jobs are tired of hearing these lecture points.

I write a lot because I want to clearly explain my points on the Internet where there's no verbal nuance. Sorry if it was too much. Are you really criticizing me for thorough explanation on a discussion forum?

Edit: I should probably qualify that in the capacity I use photoshop it's kind of a moot point anyway, since I depend on illustrator just as much and the convenience of smart objects and the interoperability with stuff like libraries are more than worth the price of admission for me.