How many large developers have recently declared themselves bankrupt? Some lawyers have precipitated this possibility by putting a charge on properties.
If you are in a lose/lose situation anyway,ie no BG, then personally, I would rather lose 30% deposit than put in 100% and not be able to sell on or it has devalued and is only worth 70-80% of original value. Many of the properties that are caught up in the illegal scandals were bought in 2002/3 onwards, when prices were highly inflated. These same properties are now worth less than they were bought for.
The current market is considerably depressed, and awash with 2bed/2 bath apartments for sale.
It is people who bought multiple properties and for investment or to flip that are likely to suffer most. Others may be able to wait years as they bought for personal/family use.
Many people cannot get mortgages because of age. They are using their life savings. To advise getting interest only mortgages is of no use to them. Anyway, why increase debt in an unsecure situation? It compounds the problem.