Personally I think the blame lies with the architects, who in turn are driven by the developers to design ever smallerprobably installed wrongly
sadly the UK heating and plumbing industry dont know how to install them..........we have an industry which has been installing condensing gas boiler for years, using flow rate temperatures that mean the boiler never condenses
Im not blaming installers I think its the customers, the govt, the training, the manufacturers etc etc
although, I would say it is pretty difficult for a heat pump to compete against mains gas, but would against oil
The installers ought to question the design, but then they have limited scope for pushback since the developers will simply choose the next cheapest quote from the bottom of the pond.
Then we switch to heat pumps, but then you can't turn the flow temperature up much before they stop being efficient - or possibly working at all when faced with a demand for high flow temperature, caused by trying to heat the house during very cold weather.
* Today, I was reading a piece that suggested the "boiler ban" might not actually ban gas boilers - allowing the use of a heat pump for heating and a gas boiler for hot water in properties where there isn't room for a cylinder