Agreed, it's tacky and indecent not to mention unsanitary. Take a look at that heiffer with her underoos riding up her crack and tell me she's  not going to spread some vile bacteria when she spreads her butterloaf self out over the seat. You can be as naked as you want in your own home and dress as scantily as you want every day. Do we really need to have people in their underwear on public transport?