As a fan of this sport since 1971, I can tell you I don't want more street courses...strictly on the basis of safety alone.
I remember a time in F1 where drivers died needlessly after hitting Armco placed too close to the racing line, because no other options existed with regard to crowd safety.
Stewart and a few other drivers lobbied 'hard' to move walls back, create bigger runoff areas and in some cases move races to safer venues. I remember that time well.
Let us not go back there again.
Although the crash structure of modern cars has gotten a lot safer as a result of composite technology and we haven't suffered any major deaths of late as a result of (DCIO) direct contact into obstacles, doesn't mean we should tempt fate.
Airborne open cockpit crashes into catch-fencing...the likes of which the'll have to use in a Miami course, negates those technology gains.
It adds an extra element of danger to drivers and spectators alike, which history and the 'pain' of past lessons have plenty of data on.
Spa and Monza...fast as they are, offer drivers 'outs' for mistakes with lots of runoff.
Look at the fence placement where there is some on those circuits.
Its located in places where you have very, very little chance of contacting it.
Miami will not have the ability for such placement.