You must be looking at the wrong houses and area,Look at sandbanks in poole,nearly all the houses have b&o installed,gaggenau,miele appliancesetc.
Darras hall and whinyard estate in northumberland is the same.Most of the really expensive houses I have seen around the world,have b&O or a multiroom custom install,like creston,runco projectors,lexicon,linn equipment etc.Sub zero,wolf appliances or miele,gaggenau.
Also top furniture and design classics from mies van de rohe,le corbusier,flos lamps.B&B italia sofas the list goes on,and they all compliment b&O aswell.Dont get me wrong you still get the flash harries who think a 65" lg plasma looks the nuts to show off to their ill informed mates,the same person would have chrome spinners on their car.
Its all down to personal taste not money.Most wealthy b&o owners I know are very discreet in their tastes,they have expensive tastes but buy timeless quality like expensive patek phillipe watches and classy b&o,were as the flash wealthy would have a diamond encrusted rolex and the biggest tv in the shop.
I dont want to keep naming places and other brands,but I was at marbella last month at my dads house,and was at a party in a very expensive house and it was full of b&O.The owner never had much of a clue,but told me he bought it as it was expensive and must be the best,I had to show him how to work it properly,he was clueless.He had lab 5s connected to a 9000 1 meter apart,then a bv9 beside it.I said he should have had the speakers connected to the tv,to benefit from the acoustic lenses.He then said his wife liked the look the way it was,whats the point more money than sense. ff topic slightly.