On an individual builder level it would be in their interest to raise house building to the right level. Therefore, for your suggestion to be true, they'd need to be a house building cartel controlling overall industry production. Possible I guess..
And yet the graph shows that as soon as house prices stopped growing, the amount of building dropped to minimal levels. Was watching a documentary the other day which basically said that during this period the large developers were laying off a lot of their staff, and waiting for prices to rebound.
Another problem I hear about often is how difficult it is for anyone other than a property developer to acquire the land that can have houses built on it. Many people who want to build their own house can't even get a look in. I guess this happens to small builders too. The kinds of houses these guys are providing in my area are the houses now being built in gardens and small patches of waste land. Which honestly doesn't amount to a drop in the ocean.
Around my way all the land for proposed development was bought up more than half a decade ago by the big national developers, and has been the subject of ongoing planning wars with the council ever since. The council have tried to block and delay some of these developments, and been over-ruled by a planning inspectorate at least once. The Council now aims to approve 4000 new houses by 2030. Tweny-freaking-thirty. And of course some people are campaigning that we don't need more houses (because isn't it nice to own a home with a nice valley view, and sod everyone else).
Bit of a rant, but basically the council are an impediment if nothing else, the developers hog the land, build small crappy cramped places for maximum profit, and the NIMBY's are endlessly campaigning against any and all new housing.
Their age is irrelevant.