As you explain so very well madabouthoovers, this is the way a lot of business is done. All brand names have a "goodwill" value, and, broadly speaking, this is the main aspect which those who buy the brands are after.
I saw on another thread here that one or more vacuum cleaner enthusiasts took a very dim light of what TTI and others have done with well-known brand names, and it is a point I take on board. However, it must never be forgotton that for a business to be at that point where they are sold off, there are already issues within that company, and without the purchase of it, it would likely go under.
So, take Vax as an example. They were a brand which came from nowhere, introduced a new and unique product, then took a firm share of the vacuum cleaner market within 10 years. But as I said recently, their "product" had a shelf life, and by the early 1990's their product was not what the bulk of consumers desired. I had an idea back then that the company would eventually go under or be sold off, and I was not wrong. Clearly there was much "goodwill" associated with the Vax name, and of course if you think about it, many consumers today will readily identify with name, either as the owner of an original Vax cleaner, or as the next-generation of consumers who recall their mother or family members owning an iconic and distinctive Vax machine.
As time progresses, Vax will be long forgotten as being the "orignal 3-in-1 cleaner" and will become known for the dry cleaners which have been sold under the Vax name for this last 10 years or so. In doing so, it will create a whole new reputation amongst consumers.
So long as a "brand" stays in use and there is continuity, it will work. But what I have never really understood is the resurection of a brand name long after it was last used. Three immediate examples spring to mind; Servism, Ferguson, and Grundig. All were brands which orginally made high quality appliances, and all were sold off throughout their lifetime. Yet the names have been used and dropped time & again. I can't really see the point of it, certainly it must be more a matter of convenience over reputation in this instance, especially if one considers that in all three examples the products which came later were vastly inferior to that of the originals. This, as I mentioned above with Vax, isn't quite the problem if the use of the brand name continues, but when you consider that the Servis name has recently been purchased and put into use, the consumer is more likely to recall the poor quality appliances which carried the name in the last 20 years, and not the Servis appliance as we knew them.
Thus, if TTI dropped the Vax name tomorrow and someone else picked it up in 10 years time, it's reintroduction is likely to stir the memory of a reasonably average / poor quality dry-only cleaner, and not that of a bright orange decent 3-in-1.