I agree, right now there's no point in carrying anything other than BTC and maybe ETH (and maaaaaaybe LTC) on a hot wallet, since you can't use most crypto's anywhere else anyway.
But for long term storage.. well, I do think some users are not tech savvy/careful enough to keep a dozen private wallets safe. I know that for myself, I already loathe the fact I have to keep track of so many even though I store 90% on my hardware wallet. It would be nice to only have to keep track of one wallet/key. But like I said, for long term holding I want it on my hardware wallet anyway.. so.. I'd rather wait on the new ledger app that's to be released soon!
I use LTC more often than ETH because it's usually faster. Everyone supports something different though...
There are a ton of apps out there for keeping track of passwords that keep them in an encrypted file. It just takes someone googling and studying enough to figure it out once.