Public sector workers also buy investment properties, just not the most expensive properties with spectacular price tags.
And in any case, that can be addressed directly, with a land tax. Any wasteful use of the scarce resource would then be heavily penalized, with those who engage in its waste paying a significant premium to society at large.
>>Not that the capital is used productively, or deployed efficiency in the real world, just that imaginary numbers are growing in a spreadsheet
Generally, good investments, that produce large private returns, increase the productivity of the economy. If that weren't the case, we wouldn't see such a strong correlation between liberalization of entrepreneurship/private-enterprise laws, and economic growth.
See China's pro-market reforms:
https://en.wikipedia.org/wiki/Chinese_economic_reform
Or China's special economic zones. Or South vs North Korea, Or West vs East Germany. Or pre-Chavez and post-Chavez Venezuela. Or the pre-social-democracy and post-social-democracy West.