I don't think that being a hacker in PS is necessary as long as you can provide the designer(s) links/jpegs of things you do like. I think adding PS as a req't/suggestion is completely a waste of time for a lot of people. Bottom line: you want people to be in a position to succeed and taking someone who may not be a visual thinker and telling them they must learn+use PS is a real easy way to lose a lot of great people.