...large companies have grooming standards...
This logic is such crap, and I've heard it as well. I work for the 6th and 66th largest corporations on the planet, and the grooming codes for them are officially "come with what you feel is appropriate" for both.
It's funny how that has changed. It used to be "businessmen" but then you get people like Steve Jobs, etc. tearing up the world with beards. Last time I heard it, it was "the president of the United States doesn't have a beard!"