General Discussion

But renting without the benefits and protections that a normal renter would have.

It really comes down to protecting people from their own lack of understanding.
I understand one could make an argument that just having the option doesn't force anyone to take it. However, given the benefit to the lender in these cases, I would imagine that it is very likely they would market it heavily in a way that distracted from the downsides and attempted to get people to sign up for them.

The reduction in monthly payment with longer terms diminishes very quickly. The amount of interest paid increases very quickly.

For example, take a $400,000 loan at 6%.

With a 15 year mortgage you would pay $3,375/month and a total of $207,000 in interest.
With a 30 year mortgage you would pay $2,400/month and a total of $463,000 in interest.
With a 50 year mortgage you would pay $2,100/month and a total of $860,000 in interest.
With a 100 year mortgage you would pay $2,005/month and a total of $2,000,000 in interest.
With a 200 year mortgage you would pay $2,000/month and a total of $4,400,000 in interest.

(I realize that 100 and 200 year mortgages are not being discussed - I am just included them to show the mathematical pattern)

The longer term the mortgage the (significantly) greater percentage of your monthly is going to interest rather than principle. One of the key advantages of buying vs renting is that a portion of what you pay every month remains your asset. Longer terms reduce that.

Again - I understand the argument that we should follow "buyer beware" and it is the responsibility of the buyer to do what is in their own best interest. But I also know what the corporations will do everything they can to extract as much money out of the buyer as possible.