Great points but you are missing the most important use case, and the need for it is happening before our eyes. The need for secure data, decentralized.
Equifax hack and many other large hacks are showing the use for a decentralized ledger. Corporations are constantly looking for ways to protect their data, so why not make it audit-able and make it secure as possible. Target still hasn’t recovered from the public scrutiny they faced, and neither will Equifax. Corporations will invest billions into the technology as users will finally say enough is enough.
Getting rid of social security cards isn’t enough, why not do a complete 360 using a decentralized idea?
Rather, my skepticism is with the AltCoins, and there really not being a need for them all. I think it’s a bit aggressive to be attacking the power of bitcoin at this stage, but that’s just me.