Maybe they know/hope that if they wait long enough, the superannuated stock will come back into fashion! It seems they would rather hold a load of archaic stock in their massive warehouse, rather than clear the stock out properly with genuine reductions so they are ready to retail things that actually are in fashion!
They need to re-think fashion - they should be looking at classic timeless pieces (of good quality fabric and design), fashion colours for the timeless pieces, then items which are more "of the moment" in design, or seasonal offerings (and just forget about cruise season - it doesn't exist over here).
Remember because the overall size of the viewership and potential customers, the US will always have greater economies of scale than the UK, and they will carry a greater range of products as a result (including more colourways, and sizes).
QVC seems a very conservative, risk-averse organisation... so it's no surprise that when they find something that sells, they want all their brands doing it, because brand-loyal customers might not buy a cold shoulder top from one brand but will buy it from another (as an example). What is really disappointing is that they manage to drive brands to a point where the very thing which made the brand appealing is watered down or totally destroyed (I'm thinking Marla Wynne here).
For anything to change in the UK there would have to be people in senior enough positions who believe change is necessary. I don't think anyone does believe it yet, or if they do, they don't care enough to remedy matters.