You're missing another component. What they're looking for in the data may not align with what individual groups of players want them to be looking for.
I thought it pretty interesting that in all the interviews coming out of Gamescon, there didn't seem to be any comments about healing. Seems like they still don't consider the current state of healing as an issue to be addressed.
Did you stop to consider that someone interacting with one specific form of side content for 48 hours of time played is a genuine success? There are successful full games on the market that don't engage players for more than 20 hours.
So what if the Morbol acquisition rate is low? Not everyone picking up BLU is interested in doing Savage raid content with it.
This is a good example of a case where what you feel should be valued doesn't align with what other players and the developers choose to value.