Every investor  has a different risk tolerance, comes from a different financial situation and has different financial goals.

Holding costs if renovation will be required (interest, builder's risk insurance, permits, porta-potties, lender draw request and/or inspection fees, etc.)

And/or are you willing to take the risk of being sued by the seller for not performing on a legal contract (and losing your earnest money)?

Is there a funky property tax issue that arises with the collateral that is a local municipality error and can lender quickly analyze the situation, assess and articulate the risk and allow draws to carry on or will they make the life of the borrower miserable?

House hacking isn't just about the market—it's about your lifestyle goals and risk tolerance.

One of the biggest risks I observe with flips and first time investors are instances where the project goes over budget or gets stuck in mud, can't sell and even worse the borrower doesn't have the credit profile to refinance out to a lower interest lending source if borrower is required to hold the property as a rental. 

The risks and delays are why many no longer pursue tax sale properties. 

With clay you risk busting the tiles, or even dislodging one that has to then be excavated anyway.

Not crazy, but if that mortgage becomes $650K, $700K, $800K, you begin to feel a little apprehensive and need more interest in return for incrementally higher risk. 

The tradeoff for doing it all alone is higher risk and a much slower pace.