Why do some girls not wear panties under dresses/skirts etc?

So they can enjoy the smell of their queefs.

Easy access to their pooter.

She admitted that she wasn't wearing panties because she intentionally wanted people to know. It's pretty evident that she wanted the attention and she is 'easy'. In terms of not wearing panties because it might show up under clothing is a load of rubbish. You can get lace underwear, invisible underwear, french knickers etc.
In university, you'll find some girls go clubbing without underwear on so it's quick and easy.

she was a celeb michelle heaton (not sure on spelling)

but agree with you about the vpl or see through dress/skirt etc that their are undies which stop vpl's and match skin colour so that they can be worn in them type of clothes

*vom*

Sometimes, if you are wearing something tight/clingy/seethrough then it can be unattractive if your pants are showing through it.... but its not a choice I would personally make....

how is it unattractive?

if you are wearing a dress that fits the contours of your shape and then there is a big ol' pants line going around your bum?

yeah, it kind of gives a better image of the girl if you can see that though

why not wear them special undies which are meant to eliminate a vpl?

Well that's what I'd do, but I dunno... if you are sloppy with your laundry or just don't have any, maybe in a panic you'd go bare-back.

Also I imagine some people get a cheap thrill from doing something like that?

Not me I must MUST add

Does not look nice panties especially with tight skirts or dresses and don't wear too.