I assume you live in rented property, as you clearly don't have the emotional bond with your home that most people who own property as a place to live do. One's home is worth far more than its bricks and mortar value.
You couldn't be more wrong with that sentiment if you tried.
But you said they would be compensated fairly - market value isn’t fair if they have no choice to move.
They could have just finished racking up debt improving their home to their desires, then you force them out of that home, leaving them with the debt but not the home of their dreams.
Not getting your money back on improvements is tough if you choose to move, but not fair if you get booted out to make other people money.
If that debt is matched by an increase in market value for the property, then there isn't a problem. The debt would be wiped out by increased CPO payments.
If you're over-developing your property for its market value then you have problems without CPO ever coming into view. You can't plan everything on an assumption you'll live there forever. Developing a property that you own is taking a risk, which can have a payoff. Creating the expectation that people will always get repaid for the amount they put into a building means detaching people from economic reality, and that something is only worth as much as someone else is willing to pay for it.
These sorts of schemes might seem attractive in terms of avoiding the political capital cost of building super-Milton Keynes out in East Anglia or somewhere, but they have enormous costs in terms of political capital when you get the television showing endless interviews with photogenic people forced out of their family homes and dumped in flats with huge "management charges" that will inevitably bleed them dry with a far worse quality of life.
Especially as people now expect they will be semi regularly ordered locked into their houses by the state in the future.
It is much easier just to bury the railway (either into a trench or into a tunnel) and be done with this, not tear down millions of housing units to avoid building a new city somewhere.
(Even a polder in the North Sea is likely to be more cost effective than mass expropriation and demolition)
The primary reason is the population of Scotland simply isn't growing significantly.
There are also enormous costs in terms of political capital when bright young people aren't able to afford a house where they grew up, despite being better educated and better paid than their parents were at the same time.
There are also enormous costs in terms of political capital when you build on the greenbelt, by adding onto existing towns which are not sized for the new level of population.
There are also enormous costs in terms of political capital when you work out all these new suburban sprawl homes are an environmental and economic disaster. Most new housing estates basically require you to own a car, as they're too far away from existing services and too low density to be able to have their own. When people start having to pay for the carbon costs of heating detached noddy homes (having four walls and your own roof means lots of places for heat to escape) and the costs of driving about, they'll get a fright. The people living in denser urban areas will not.
There seems to be a strong mental block in some people on this thread. They can't imagine towns growing
up as well as
out. Larger towns and cities need to be built more densely at their centres to be sustainable. However, the process of building
up necessarily means replacing existing buildings. Towns and cities across the world have seen buildings in their centres replaced again and again with larger and denser ones as the town grew around them. This didn't use to be controversial. People didn't mind knocking down rows of old cottages to replace them with the then-new terraces and commercial buildings we have today in most towns.
If nothing else, when you grow the town population, you need to have wider roads to handle all the new traffic. Some very historical towns and cities have avoided the need to redraw the road network by creating a sort of inner ring road that divides the old and new areas. However, on the other side of these roads, they started building high density, not sprawl.