I hope that I'm not the only person getting an advert for shoes at the bottom of this page.

^
Personally, I don't understand why someone would want to walk barefeet in the plane, or even worse, go to the lav barefeet. But I don't get upset over that as long as I don;t have to share bed with them or my house for that matter.
In some societies, Japanese, or traditional Indian, shoes are segregated by their function. Different pair of shoes for bathroom, for the rest of the house, and yes, for kitchen too. When I was growing up, we had a separate pair for use in the kitchen. Shoes worn in the kitchen were never used to go to the lav or vice versa.
Shoes used for the lav were only for that purpose. he level of cleanliness needed and prevalent in different living spaces were visibly and aromatically (for lack of a better word)different. Now the visible/aromatic lines are blurred and some people forget the difference. If they do, it's their loss.

When I first came to the U.S., I was baffled by signs such as "Customers must have shoes on to enter the store". I asked my friends. No one could give me a satisfactory answer other than, "The store doesn't want to be liable if you are hurt by debris, say, broken glass, on the floor." It made sense for the business owner in order to lower his/her liability. But it still evades me, to this day, how it protects other customers. The same owner centric argument applies to the airline/aircraft, except it becomes more cogent in the event of an emergency.

If the lavatory is not clean, it makes little difference to me, if someone does or does not wear shoes to venture into the lav. The filth will still be transported from the lav floor to the floor in the other parts of the plane. But it does make a difference to the restroom visitor, whether they do or do not wear shoes into the lavatory.

There are interesting examples of how such practices differ.

For example, a Bahai Temples(House of Worship) accommodates local laws and practices. So in the US, you are required to wear shoes when entering the Bahai temple. In India, you are required to take them off.

When entering a Sikh place of worship, men must cover their heads; in most Western situations, they must remove their hats.

I think if a religious ceremony, or a rite has to be performed without shoes, it makes sense to take them off before entering the place of worship. Do Bahais normally worship with shoes on or off?
I have never entered a Gurudwara (Sikh temple) in the U.S. Do they expect you to remove shoes?

You are expected to remove shoes when entering mosques, functioning ones, at least for the ones I have entered and I have entered mosques in more than a few countries.

Or at the very least - not have cankles.

I always wear driving shoes on long haul flights due to their slip on/slip off ease both for security screening and for the flight. I have comfortable, thick socks I generally wear on the long flights as well. I slip the shoes off when I am in my seat, then slide them back on if I need to go to the lav or want to stretch a bit. It's a pretty simple fix.

I don't really know. However, their temple in Wilmette, Illinois requires visitors to wear shoes. In Delhi they have to remove shoes. No worship or service is involved in either place, this is for casual visitors looking around.

I think it's just prejudice. Many restaurants, for example, claim there is a law or health regulation prohibiting barefoot customers, but this is false, and as you say, doesn't even make sense. One customer being barefoot makes no difference to the health of other customers.

Exactly.

I find myself thinking of health clubs in many European countries (especially Germany) where you must wear a bathing suit in some areas (such as the pool) and must not wear one in other areas (such as the sauna), even though both areas are co-ed.

Ya mon, its no PROBLEM!!!! No problem at all mon, haha

Smart. You can make a pair last twice as long. But surely, it must be rather inconvenient to have to hop. :p

I see a lot more skin exposed that I never want to see ever in public places, especially on planes and not on feet.

Wouldn't like sitting by the sick, stinky, overflowing, loud ones either, but the topic here is bare feet. If you are sitting next to strangers, a significant percentage are going to be offended by bare feet on the seat back. Way too up close and personal for strangers on a plane. Sandals on the floor, that's OK by me.

They stay in my carry-on (which is why I want them as light as possible) and are only used in flights, so should last forever. :) They are all cloth, no rubber or leather, so can be machine washed.

It is against airline policy to bare feet on board and place on furnishings?
 

I'm not sure what's worse: the guy in coach bulkhead with bare feet propped up on the wall, or the FA making a big deal about it, telling said passenger that it's against American Airlines policy to have bare feet and that it's not a living room....