Shopgirl-I understand your feelings, but I think the original thought was about the initial interview. After that, one must weigh where they are headed and who is in charge. Be realistic everyone, the person signing your paycheck is PROBABLY over 40 and THAT ALONE is a hint to attire. I keep going back to Collin-"Know your audience."
In most cases, once you've sealed the interview and gotten the job, the dress code will relax...UNLESS you are in a promo position. Then, it depends on what you're promoting. Just remember the basic rule from rush to real life jobs. It's better to be a little overdresed than underdressed. Why would one take such great care during sorority rush and NOT for a job interview???
They are PAYING you, and in a sorority, the fact is, you are paying THEM!