In my opinion, it's not lack of HDD minable coins, or lack of interest by the public, it's more about which problem the coin will solve? Why not choose any other available coin?
The problem the coin solves doesn't matter much anyway, since most of these coins are just copycats or base their "problem-solving" on features that major coins like Bitcoin are said to luck.
Numbers do a lot. Have you noticed how shitcoins pump in price for no reason except that everyone is just hyping them?