People think taxes should be used as a means of ~~social~~ economic manipulation. We also need heavy default-YIMBY laws which make it easy to build lots of new high quality units.

Taxes should be used to assure that assets get deployed toward productive gains. For the same reason that a nation doesn't want a deflationary currency -- capital should be deployed, not hoarded. Real estate holdings are moderately deflationary these days. Doing nothing with your real estate is often profitable. That's an actual problem that taxes can address.