Earlier quoted context omitted.
Flippers are like canaries in the mine. They are usually leveraged like crazy on short term loans, not flipping the house quickly can be fatal to them. Rental won’t let them pay off there loans when they come due in a couple of months.
Cant rental (ie, passive) income be used to secure additional funding? I know that was the case when I considered buying property to rent back before the 2008 crash (I ended up not doing that, luckily).
What I suspect happens is that once you reach some number of properties, you become a commercial borrower, and different rules apply. A former coworker owned most of a street of duplexes at one time, and he had no problems getting loans.