Because if you don't have an offering that'll make it do something interesting OOB, it's unlikely anyone would buy it. [bootstrapping from true scratch is typically a nightmare for hobbyists]

I shouldn't be quite so negative; NV did put in a lot of effort building up the development kit. ARM Builds of CUDA, drivers, etc. Repos with packages for the job. Tutorials for common tasks, etc. They're really within a hair's breadth of an excellent OOB experience, but fell at the last hurdle.