It's not inherantly a bad system, quite the opposite. I am sure the devs will return to it.
The issue seemed to be that it sits on top of other systems. These other systems are still too unstable to further complicate with trivariance at this stage.
Additionally there was insufficient support architecture in place for trivariance from the perspective of the player. I mean insufficient ability to manipulate the values.
I like trivariance and I'm sure the devs do too. I'm just parroting my recollection of their past statements mixed with opinions of mine. There's a lot of potential in it.