Are they all just buying and speculating on market appreciation?

I am speculating that the “fully rehabbed”, “tenanted”, and “property managed” property sold to the unwary investor, will be with WITHOUT a safety margin, likely at full retail price (a big no, no), or even at a premium.

Do some investigating to confirm your speculated numbers.

You'll be basically speculating on appreciation. 

I remember when the insanity speculation took over in 2004-5.

If the property is rural and qualifies for an agriculture or wildlife exemption, then taxes will be almost nil so the cost/benefit analysis is much simpler.Buying undeveloped lots in a residential neighborhood is more speculative, in my opinion. 

I'm originally from Seattle and it's more speculative there with maybe the 0.5% rule and 4-5% cap rate.

So we do not have to speculate too much about the next 10 years, since we have the worst 10 years right behind us (future lurkers, I am typing this in December 2017)... how does an average home's value in San Mateo in 2007 compare to 2017? 

At 6 months the market is revaluated and the process begins again, after one year it will be written down until it sells as banks can't hold REO/ORE as banks may not speculate in RE.

Florida is a good place to live and a great place to visit and retire to, so our growth is mostly dependent on tourists, retirees and speculation.