edited my post for a little bit of clarity.
im assuming this tracker is made for relic to keep track of all the issues at hand. balance and meta concerns are already being discussed in the alpha forums believe it or not, and relic is aware of most if not all the balance/meta concerns anyways.
it would just be more convenient to have just bugs because right now the 'major issues' category includes both bugs and balance issues. you would have to sift through subjective posts to find bugs that need fixing soon.
Ah, I gotcha. I think the intention with this is to allow the most prevalent issues to expose themselves via upvotes. If the majority of committed community members find the isu, for example, to be a major issue, it will quickly garner the most votes and thereby create a sort of focused priority list. Obviously this is only useful if enough of the community decides to participate, small sample size and all... If nothing else it is useful for identifying community sentiment, biased or not, on issues. Relic is obviously going to asses the points expressed at their own discretion.
The whole point of the cards is to make all issues available at a glance. The bugs can be identified easily by the labels provided, which eliminates much of the time it would take to identify the same issues by browsing the forums.