What? Ranking by the number of likes/upvotes (which is the method I see when looking at the Hot view) is not "ranking ideas based on the importance of the issues they solve."

I know CMU teaches actual algorithms for this type of ranking, because I went there. :P

Issues are a bit simpler in that they mostly are based on activity related to them. However doesn't it make sense that an issue that's popular would reflect the magnitude of it's importance?

Not exactly. You're confusing correlation with causation.

On sites with Reddit-like rankings, the number of votes which a submission receives is one of the primary causes for the subsequent number of comments/activity of those respective submissions. And "importance" is not necessarily causal to submission ranking (aggregators are weird).

Nothing on the site seems to force people to implement solutions to the problems - which means it's an option not a requirement of the service and definitely doesn't "come first."

I think there is power in a "pain-point" ranking service, if that is what you guys are going for. Definitely needs to be redesigned to make that clear if that is the case.