Why doesn't everyone use RenttoRetirement?

[Quinn Barnett]

Now I know it is not for EVERYONE because some of us are out there getting slamming good deals, but rent to retirement has realitively low barrier to entry (18-35k) and has pretty great returns (12-18%). Why are more people not jumping on that if they don't have great deals locally or enough leads? It seems pretty great. 

I am asking partly because continually saving up for a R2R house every 10 months might be my next investment plan and want to see the cons.