I used to have a friend who's family made me take my boots off ... I used to wear army boots with 24 eyelets, it took me about a minute to take each one off, then another minute to put 'em back on!
Since then I vowed to never enter a house where they make me take off my foot wear.
On another note. After I moved out of the homeless shelter, they have a person who comes to make sure you're keeping the place clean, paying bills ETC. During 6 months of this period a college student was working with her.
Anyway, after I got my carpet fitted they come round to check up on me. I let them in, then walked off into my living room, they took there time to come in and I wondered what was taking so long, when they come in I realize they took there shoes off.
I just laughed at there over politeness, especially since I was wearing big work boots.
I think when you go into somebodies house and get your shoes off, it conveys a "making yourself at home" or overly familiar impression. I think it's like meeting somebody for the first time and hugging them, it's bit forward.
If somebody asks me to take them off I think it's quite bossy, after all you have a hoover and even vacuum's that wash your carpet at the same time ... not to mention no matter what you do, your carpet will get dirty.