You make some interesting points! I've always seen those 30 year mortgages as an absolute chain around a person's neck, yet the seemingly "accepted wisdom" of our age is that if you rent you'll always be poor; that really does appear to be true now with landlords extorting the f**k out of everyone they can.
Most people aren't looking for assets they can "leverage 5-1" though, they're just looking for a place to live and a roof over their heads, yet can't afford it. If they could afford to gamble in the stock market, they would probably be doing that as well. Mortgages are usually the only relatively safe debts that consumers can take on. The risk regardless is worth it because we have somewhere to live. Stocks and bonds don't shelter you from the rain and they're far more risky.