In an earlier post, I argued that it is really stupid that in Britain the cultural norm is to wear shoes in one's own house and the homes of others. I believe that there is a powerful social stigma against hosts and hostesses that prefer visitors to remove their shoes. It is thought by many people in Britain, that such people are either excessively house-proud or that they are obsessive about hygeine and cleanliness. This stigma is so strong that I know people who certainly are obsessive about cleanliness who would never ask a vitor to remove his or her shoes. Being proud of their supposed tolerance, most British people would respect a Japanese or Thai requirement of shoe removal, but would never tolerate such an expectation from a British person. The stigma against shoe-removing by British people is related to the 'Lady MacBeth' factor- an excessive concern with cleanliness is considered very suspect by British people. Britons are probably less concerned by dirt than other people's (that old British stoicism) and there is a common belief amongst many that a certain level of dirt is rather healthy.
I think the main reason for the opposition to the shoes-off policy is the importance of class in the British mindset. Every middle class Englishman or Englishwoman dreams of being upper-class; and no upper-class person would expect their guests to take their shoes off. If you have money, you can afford to have your carpets cleaned regularly and if they wear out, you can afford to replace them. Hence, if you worry about keeping your carpet clean or wearing it out, you are obviously short of money. British people just have to keep up appearances (ironically, I believe Hyacinth Bucket, the heroine of 'Keeping Up Appearances' has a shoes-off rule. This shows how common she really is).
There is also a powerful stigma against people with 'smelly feet'. Many people are terrified of being exposed as having 'smelly feet'. It seems to be that this is quite irrational- most of the people I have met who claimed to have 'smelly feet' did not create any noticeable aroma after removing their shoes. The only strong foot smells I have encountered are from people who did not wash their socks regularly. Do people in countries where removing shoes is the norm never have smelly feet? The answer is probably yes and no. I suspect that most peoples feet in such countries probably smell a lot less, because shoes are removed more often. Thus, the people in Britain who fear exposure of their 'smelly feet' would find that their feet would smell a lot less if they took their shoes off in their own home and other people's homes. It is probably the case that in shoe-removing countries, any residual foot odour is either ignored or not noticed. Also, the practise of providing guests with slippers, as in Japan or Eastern Europe must considerably reduce this factor.