Like @John Underwood said, even if there are a ton STRs in an area, you can still do OK.If tourism starts to fall off in an area, saturation becomes more of a problem.

Some areas are definitely better for tourism and depending on the length of the high season and rates you could narrow down the best areas, then look at purchase prices, the expenses and management costs.

You have a strong economy fueled with government jobs, military personnel, tourism, retirees and recently large amounts of commercial infrastructure is coming to the area.

The average STR owner spends much more on home/property  improvements because they have to in order to retain a 5 star rating.c) Having these STRs in pristine condition raises the property values of the neighborhood, thereby raising the property tax eventually.d) Studies have shown that a strong STR presence in a city will actually raise tourism in that area.

You have a great point that I hadn’t considered, but I am in agreement with you.Further compounding the issue, at least in tourism areas, is the phenomenon where wealthy folks buy old homes that were being rented by the room, and replacing them with summer mansions (or winter mansions) and the supply of rentals continues to dwindle.If we’re already at a deficit of rentals, and aren’t building enough, then you’re right-we can’t become a “renters nation”.

It's inconceivable to me that since in each case the whole town's economy is tourism and STR's make that possible, that the locals would allow any changes that would kill the town. 

Recent population growth has all been net inbound migration, which is slowing.

And yes people get upset sometimes with outbound marketing, doesn't matter your industry it's the price to pay... if you cant handle that, try inbound marketing like PPC they are usually softer. 

Find an asset, underwrite it to a high scrutiny and talk to local professionals to see how the climate has been for tourism and STR's.

However, considering Canna-Tourism is a $17Billion industry, I find it hard to believe you couldn't be successful if you put some intent behind it.