Greetings,
...wow... The weirdest part of reading this thread for me is that I'm the opposite of many here. I wouldn't consider being out of my hotel room in anything but jeans (or better, although I rarely go better), but barefoot is just part of my life.
I can't count the number of hotels I've been in where I've barefooted it down the hall to the soda machine or ice machine, for instance. I've even been known to barefoot it down to the front desk to have a chat if I need a particular service, or pick up something immediately needed from the little mini-stores in the hotels.
Everyplace in most hotels is carpeted, and comfy against my feet, and I really hate wearing shoes once I've gotten comfortable. (And flip-flops are NOT comfortable for me, they keep falling off.) I've never gone out eating while barefoot in a hotel, and for personal reasons I probably wouldn't (I feel an overpowering urge to dress up to the average level of the guests, and that would generally include shoes) but I wouldn't think twice about walking the halls barefoot.
All that said, PJs and/or bare feet on others don't bug me (especially in a beach-themed hotel or area). One reason is that I'm a long-time Science Fiction fan, who's attended a LOT of conventions, and so what I've seen in hotel hallways and common areas would evidently strike dead a number of the blue-hairs here.
But really, how different is a bikini bottom and top than a bra and panties? It's *purely* a matter of context and/or intent. The same context/intent issue is true of the bathrobes, for instance. Because you see them as bathrobes, you see them as something private. Because the other guests see them as pool-robes, they see them as intrinsically public. Neither is strictly wrong, as the robes may serve a dual purpose. (As a bikini bottom worn under a skirt contextually becomes underwear, and people may feel uncomfortable if they become visible, even though they may have been wearing them openly just minutes prior.)
Irregardless, I believe strongly in an engineering paradigm that roughly translates as 'Be open in what you accept, be careful in what you present.' The idea being to accept others mistakes, and differing interpretations, but try not to make any yourself. It's a powerful idea in the engineering world (it made the Internet possible!) and not a bad one socially.
-- Morgan