I get so irritated by these so-called 'etiquette experts' who continue to insist that it is impolite to ask guests to remove their shoes. Who made them rulers and judges over us?
There is no absolute bible of etiquette. There are certain courtesies that most of us are agreed about, but other than that it is a matter of opinion.
When reading travel guides, I have often found they disagree about the details of foreign etiquette. For instance, I have heard conflicting opinions about saunas in Finland. One guide said that one should never refuse the offer of a turn in the sauna; another said that it is perfectly fine to chicken out of a nude sweaty session in Suomi.
On the subject of removing shoes in Japan I have heard conflicting views. Obviously, In Japan you remove your shoes. But do you turn them around to point to the door after removing them? Some say this is the host's responsiblity, others that the guest should do this. Some say that you should always put on the slippers offered by the host (which is a pain because they seldom fit differently shaped western feet), others that you can decline them if you like.
Etiquette is bunk. It is just a matter of opinion. I have no regard for these so-called "etiquette experts" at all.
Etiquette has changed. I read an old etiquette book that said that it was more polite to enter a house in muddy shoes than to remove them. I imagine most hosts today, even those who do not prefer shoes-off would be horrified at the thought of somebody coming in their house in muddy boots. If it is not acceptable to remove shoes in homes, surely it is also acceptable to politely request that they are removed?