It must have something to do with the society around graphing calculators. The forums were always supported by mostly bored students with a few experts, but they aren't coming like they used to. Is the graphing calculator in the classroom dying, or are students just not curious about pushing the abilities of graphing calculators anymore with all the newer tech?
It may very well be that they are on their way out.
As previously mentioned, Germany ditched them and some other countries are switching to boring tablets.