There really is no debate. Sure, there are people who have used solid wire "with no problems", but the fact is that crimp connectors weren't designed for solid wire, and solid wire necessarily breaks more easily than stranded wire, which is designed to be flexible.
We bend a lot of rules on this forum. Also, I'm sure that being cheap is often a factor, but I think most people use solid wire just because they don't know better. There's a lack of a trustworthy repository for basic building questions on this forum.
I guess if you have to do something wrong electrically, use the wrong wire for CP... rather than use too small of wire for your AC lines, which is far more dangerous.
Wade