Mouse, Cortex and Dr. Lynch have had a lot of detractors over the years, and the AMPA upmodulation concept was originally viewed with extreme skepticism in scientific circles. However, as the recent LA Time's article noted, Lynch's AMPA centric view of LTP/memory is now pretty much the consensus view. Dr. Lynch made a lot of enemies over the years though, and some of them are probably happy to gloat over Cortex's current misfortunes.
There are numerous facets to the Psychiatric decision, but as Neuro pointed out, probably the most important one is the current hypercautious mindset at the FDA over ADHD drugs. This factor likely outweighs everything else, and stacked the deck against us. Other likely factors include previous AMPA related failures "poisoning the well" to some extent (LY-451395, CX-516), antagonism to Lynch, etc. Who knows, there might even be some legitimate FDA concern over the possibility of actual long term AMPA toxicity. Extreme FDA butt covering is most likely the main factor though.
Regardless, this leaves Cortex in a real pickle, with its future prospects in serious question.