For years now homeowners have used HELOCs (Home Equity Line of Credit), to effectively 100% finance an additional home purchase by using the HELOC for the downpayment, and a mortgage for the rest.
This puts a lot of people in (very self-inflicted) financially precarious situations where they are counting on interest remaining low and the value of their investments going up in order to stay ahead of the payments.
Regardless of how we got here, due to this situation no government will screw all those people over just to "fix" things for those who haven't been able to get into that market yet.
It's a lose-lose.. Leave things the way they are, and you continue to price out an entire generation, which is a huge problem. Make a large corrective change to address this and you potentially force a huge amount of existing owners to sell investments at a loss and face financial distress, another huge problem.
Some folks say "too bad for them for getting so leveraged" but all they did was follow the advice given to them by the market, and follow the rules that our government put in place.
Anyways, it's a complicated problem. Foreign ownership certainly contributes to the problem but it's not the major factor. This is 100% a "for show" measure.