I also have many typewriters dancing around at home, and of course I love seeing them there, they´re beautiful pieces of engineering and a good place one brings life to your house. That´s the extremely good part of typewriters as decorative objects 
But what I wanted to focus on was on the bad part, and believe me, I´m having a hard time to explain it because I can´t find the appropriate words! What I´m thinking about is like when people use books as decoration. I mean, it´s as if you buy a bookcase and you fill it with books which look good. The red ones for the upper shelf, blue ones mixed with green ones at the middle, then a couple of bookstops which could be two colourful typewriters and at the bottom some kind of 20-tome encyclopedia. And you´re never going to read any of the books, and they could even be false books for that matter (like props from a movie).
Thhat´s why think selling typewriters as decorative pieces while targeting at a high spending public who don´t even remotely care is absolutely wrong. Yes, if you´re willing to pay nobody´s going to stop you, and the same goes for the books. If you want to use them for decoration because they give your home an air of "cultchor" and "nowlech", good for you. You´re unmasked, congratulations.
This may sound be a bit too extreme, and maybe I can´t exactly tell what I´m thinking (the language barrier, sorry
), or even maybe I´m overshooting it, but it´s a bit like that thing with the crushed typewriter at the press. That, somehow, fells wrong.