Are you saying that the sphinx progress is at that same level currently as the state of the art in the 90s? Surely that's hyperbole.
Also, using AI to generate even better models doesn't seem like a bad idea, if you're looking to improve it -- the fundamentals of speech recognition haven't changed, why build a completely separate open source product instead of contributing to something already well understood and accessible?
Kaldi does support neural network models in addition to good old HMMs, but it is very "researchy": everything is set up so that you can replace any step in the pipeline by your components (and then publish a paper about your results). But that also means that you pretty much have to be an expert to correctly assemble a working product from the available components, and it's pretty much assumed that you will be training your own models, which can be difficult when you don't have access to lots of data.
So yes, the existing landscape for open-source speech recognition leaves something to be desired, and the focus of existing projects doesn't necessarily lend itself to turning them into what you want.
neural network models have their own downsides, the biggest one of which being training -- why throw the baby out with the bathwater instead of taking the approach kaldi has taken, possibly building a neural network model alternative inside sphinx?
Let CMU plug away at making HMMs better, while you plug away at making neural networks better, but interoperate so everyone gets both benefits? You can even maybe make some headway with the neural network bootstrapping problem with some help from the progress CMU has already made.
Sphinx is like that.