Well, reworking the group finder wouldn’t require that much budget. It’s not like they’d be creating a lot of graphics assets or ability designs.
^ Goes over in more detail where a lot of the problems lie, and how they can be addressed in various ways.
And then there’s the solo queue for being matched but not for queuing up as I linked to above.
There are many things that can be changed, with very little cost. The question is if there’s the will to do it by the higher-ups in Blizzard though.