They do this because they need investments, and all other forms of investment are less appealing due to regulation/risk. They need investments due to the misguided economic cargo culting that inflation is necessary, to promote investment. So the people invest. In property.

You can see this magnified in China where traditional types of investments are unavailable, so the property bubble is constantly growing as it is constantly bursting.

People follow the incentives, and not just the incentives set by the government, but the incentives of reality. If you drop a boulder, the river doesn't just stop; the river flows around it.

small correction. People who legally immigrated earlier are the most vocal supporters of stricter immigration rules for future illegal immigrants.