I don't see the problem with the price for cartridges. A 64GB non-rewritable flash cartridge should be less than $1 to produce. Sure, Blu-rays are just a few Cents to produce, but it shouldn't matter that much for $40-$60 games. Don't try to argue with the prices of BD-ROMS or SD Cards for consumers, that's ridiculous.
Optical disks have to go, they're antiquated tech compared to other components in today's consoles.