At some point, the scales will tip and then everyone left wants/needs to jump off in order not realize coming loses.It is a cycle, like most things in life, but one that can be avoided if you stick to what actually works rather than taking unnecessary risk just to force a deal.

Basically, the higher the ROI you want, the more riskier properties you'll be forced to target.

That forces them to figure it out.

But if the docs give you the right to start charging default interest, force release of the lien etc that is at least some leverage, control. 

Further, the reason for sale sub to may be because of some property deficiency that does not allow the property to qualify for new financing, or the property may not be worth the amount owed forcing the seller to “compensate” a higher than market price with either “easy or no qualifying” or a low interest rate.

Without it, there's no guaranteed legal status, which could lead to being forced to leave the U.S. and potentially manage property from abroad—a complex and often costly endeavor.Real Estate Ownership and Rentals as a Non-Resident: If you do decide to purchase property and then move abroad, you can keep it as an investment, but it requires navigating tax regulations specific to non-resident foreign property owners.

The lender can using the acceleration clause of the mortgage make it 100% due and payable but that would just force you to refinance it into a different kind of loan.

Also forces the seller to deal with the deposit reconciliation. 

Their method of “forced appreciation” is kind of interesting.

The social peer pressure among the group will usually force them to figure out problems/drama that otherwise would be much harder if they're not in the same social circle.