That might have been the case years ago, but its not always the case. Tho, personally I think it should be. VX says biz casual and I know Atlas tells you not to wear a tie.

Also in the non-aviation world, my friend went to an interview for an IT job. He wasnt gonna wear a tie, possibly not even a suit. I told him to wear one, so he did. When he got back my friend said "F*&*& You, XXXX". He told me the interviewer (who was pretty high up in the company, possibly the VP) was wearing a Hawaiian shirt or something like that and commented on why my friend was so dressed up and was probably the best dressed guy in the building.

Times have changed, I remember wearing a suit to my job interview at Montgomery Wards years ago for a part time job.