Man, you people are a bunch of squares. Who cares if people wear their PJs or slippers out in public? If I had my druthers, I'd never wear anything but pajamas EVER AGAIN.
My objection to it is twofold:
1) Something resembling public decency -- I'm sorry, I don't care how cute your spaghetti pajama top and cute little ducky bottoms are, it's public, put your shirt on. Is it so hard? It's not exactly as if you need to wear anything more classy than T-shirts and jeans for this campus -- just look frickin' presentable. Pajamas are only acceptable if you woke up two minutes before your class started and
ran.
2) Careless and slovenliness. I realize that I'm a bit of a neatnik about clothes, but what you wear is your image to the world and your assessment of the surroundings. As Miss Manners taught me so long ago -- dressing inappropriately for an event or location is expressing disrespect for it and those around you. Going to class in pajamas (presuming you had enough time not to) says to me "I don't respect my school, my profs, or my classmates, or I would have gone to class in something only slightly less comfortable than pajamas and a thousand times more decent-looking and presentable, and I don't respect myself enough to take 30 seconds' effort on my appearance."
So... yeah, I'm a square.