If you're looking for the simplest possible developer setup for Sitecore then creating an ASP.Net web project, dropping Sitecore over the top, configuring it for shared databases and checking it in to source control is the answer. Back in the day it was an accepted pattern to to work this way – so you could click "play" in Visual Studio to run your site. And I still find myself workig on projects running that way. But today this is considered a bad idea. So why do I keep finding projects set up this way, and why isn't it a good approach?