won't fix anything
> don't let them get loans without taxes againt their illiquid wealth
You don't want to fix this. It would kill repurchasing agreements as a collateral damage, making access to credit more difficult and expensive for everyone. Not to mention HELOCs. You might say, "ok, exempt HELOCs", but that's just an arbitrary goalpost.
The economy is organic, you can just use a wrench and have a go at a couple of cogs and expect there to be no knock-on effect.