They say people aren't dressing up to fly anymore--and it's probably the same reason they aren't dressing up for work: the treatment you get doesn't deserve it.
Still most companies have dress codes which you find out about when you transgress them. These codes usually appeal to "common sense" and "good taste" even from companies that make you wear sun visors indoors, headsets to answer the company phone while doing another job and buttons advertising Kwell shampoo at your collarbone.
Memos usually begin banning jeans, shorts, cutoffs (remember cutoffs?),T-shirts, tank tops, undershirts (aka "wife beaters") sweat pants and workout clothes (read: Lycra and Spandex), tennis shoes, boots and sandals.
Then the memos add their updated-since-1999 codicil which bans visible underwear (thongs), low risers, tattoos, inappropriate jewelry and "extreme hair colors and styles" fearing an employee corps of Amy Winehouses.
But of course there are plenty of loopholes
Is a tube top a "tank top" or a "bare midriff"?
Are crinkle cotton gauchos with a draw string "workout clothes" or "shorts"?
Are flip flops with plastic flowers sandals?
Under what category would an axle-grease-covered blue-jeans jacket be banned from a boyfriend who said he was coming right back and you're still waiting?
At what point does a do-rag become a bandana?
The 1980s comedian Joan Rivers used to say you know it's going to be a bad day when you crack open an egg and find pantyhose in your skillet.
Companies have stopped selling pantyhose in egg shaped containers--and stopped selling them at all for that matter--but women have retained their antipathy toward them.