But those people in country would be paying national taxes either way. It isn't like if Vancouver stops a rich person from Toronto investing in real estate that this person will leave their millions of dollars in a checking account instead. They will find some other way to invest their money.

If you are solely worried about the tax base, wouldn't bringing in foreign investors into real estate investing while letting domestic investors focus on some other investment vehicles lead to more tax revenue?

Perhaps. It's not hard to imagine that having additional competitors to local real estate with the result of driving up prices is not in the interest of the locals, who need places to live.

That one group has less stake and can be discouraged through legislation while another has some constitutional-like protections is not a compelling problem compared to the one in the paragraph above.