Sure, people can pretty well wear whatever they want,singlets,footy shorts and thongs included.
It's a free country.
I'd never wear thongs on a flight for quite a few reasons.
They don't offer much in the way of protection,stub a toe in some places(spit, dog cough,general mank) and you're just about guaranteed to pick up a nasty infection, if you break a strap (yes, even with the mighty double pluggers)you are going to have to either fix it or get a pair of shoes before you are allowed on a flight, and the indescribable filth that coats your feet just from walking around.
Singlets?
If you are a blokey bloke, you'll have a vast forest of shag pile crusted in either a Brut 33 equivalent of C.S gas or have an eye wateringly acrid pong wafting from your dank pits.
There's a social contract we've tacitly made that we don't go around reeking if possible.
Even a T-Shirt will contain some of the stench not to mention the fallout.
Fallout?
I dunno about you, but I don't want to have to pick someone else's arm pubes off my seat, clothes or meal.
Shorts are O.K, we're a shorts wearing nation, but please make sure they contain the massive serve of meat & two veg.
No one in their right mind wants to see your hairy bollocks when you sit astride your seats.
A minimum of clean shorts, T-shirt and a pair of enclosed shoes, is that too much to ask for?
Do you really need to stick it to the man by wearing yob gear?
So, if you want to be a slobby, inconsiderate fellow traveller, go for it, it's your choice.
Those that have a modicum of respect for themselves and other air transport users will dress accordingly.
