The majority of those lots circled are not for flipping real estate. The ones circled are mostly commuter lots and business lots that are often mostly empty.
It might be a matter of perspective, but a mostly empty parking lot is not in the business of being a parking lot. Flipping commercial real estate can take decades, the point is that the lot is not required and will likely help the area become more city-like.
I'd hesitate to call that "flipping", then. Flipping real estate is usually meant to be a short term process to extract quick profit, not a decades long wait. That would be "investing".
To me, investing is putting it to good use. Buying it cheap, paving it, and waiting to sell high is not "investing". Again, that could just be perspective.
It might be a matter of perspective, but a mostly empty parking lot is not in the business of being a parking lot. Flipping commercial real estate can take decades, the point is that the lot is not required and will likely help the area become more city-like.