Imo you are right but there is a caveat. 

If the mortgage holder could borrow against their real estate with a HELCO and use the credit to buy Bitcoin then they’re accessing Bitcoin sooner and still not paying ≈ 1 million usd in rent over those 30 years to live.

I would buy the Bitcoin vs put a down payment on a house if I had the 100k and no Bitcoin. At this point the Bitcoin has at least an order of magnitude more upside than real estate.