IMO Neptune likes their costs cheaper than the plastic in their products and likely bawked at the price.
That said, the industry also seems like it is trying to make customer cash grabs and build "systems" versus products that work together. I'm surprised that Red Sea hasn't rumored their own controller yet.
Trying to make a controller ostensibly drove Vertex out of business LOL. Both Neptune and ETM have been moving onto each other’s ‘turf’ for a while now. Beyond what’s already happened, ETM is clearly on the controller path (maybe more software than hardware) and a competitor to Radion seems inevitable from Neptune. Trying to assess ‘blame’ is largely foolish and pointless. While convenience certainly is all on one platform; all eggs in a single basket may not actually be the wisest approach. I’m largely done getting all outraged over stuff I cannot control.

Don't use that or any other dry rock...
or leverage one of the (I'm guessing) already existing standards in the IoT space...

