I can give you something of an answer.
An earlier model of the Thermomix was sold in the US back in the '80s but it did not go all that well.
At one time there were many companies selling things via "party-plans" with demos in homes but that practice fell off rapidly once the internet came into being and people could order things online without all the hassle of someone trying to promote a product.
I used to cater parties back in the late '70s until the early '90s for Tupperware, Princess Homegoods, Pampered Chef, Avon, Mary Kay, Amway, Creative Toys and etc.
Very few folks that I knew remained in the business after the mid-1990s. Too often the goods were overpriced, compared to bargains in superstores like Walmart and could be found at a discount online (Pampered Chef, for instance).
I guess the buying public just got burnt out on this type of sales promotion. Few women are now stay-at-home moms and when they get home from work they want to put their feet up and not have to schlep off to someone's home to get a sales pitch.
Also the economy is still too iffy for most people to spend that much on an appliance, even though it would eventually save them money. California has been hit hard. A neighbor down the road just got a notice that her hours (high school teacher) are being cut back in January.