If you think all the talk about regionalism is because it's a good idea, you need to think about the appeal of "one size fits all" clothing.
The fact is it can be worn by all, but fits no one. It appeals to politicians because they become less accountable and more distant from the concerns of taxpayers. The advertised "economies of scale" have not been evident in other cities that have tried this form of government. And think about the gross inefficiency and unresponsiveness of county government. They do one thing well: declare tax increases.
Regionalism is a Trojan horse containing bureaucracy, inefficiency and unresponsive government.