Alright, so let's call them cryptotokens instead. I've always preferred that myself, it's a much more general description of what they do. It doesn't change what they are but if that term makes you happier we can go with that.
It renders it useless outside of as a bit of gambling on the side.
Hardly, there are lots of things you can do with these things. A ledger is more than just for tracking money, it's a database. You really can't think of useful things that could be done with a completely decentralized and permissionless database?
Bitcoin, no, because it's a hopelessly out of date blockchain that actively resists having new capabilities added to it. Ethereum, on the other hand, is designed that way from the ground up. Many of the other smaller but more modern blockchains are also like that.
You can't use them as a currency everywhere. But the same can be said for any other currency too. You can't use US dollars everywhere. You can't use Chinese Yuan everywhere. And so forth. A currency doesn't have to be universally accepted everywhere on the planet for every application before it's useful.
Regardless, I was talking about using Ethereum as a distributed database.
I really don't see your point here. I'm agreeing that you can't use it for everything. But what's wrong with that? There are plenty of things in this world that aren't useful in every circumstance and yet that doesn't mean those things are worthless. Use them for the things that they're good for. Elsewhere in this thread I listed off a whole bunch of non-stock, non-currency applications that have been built on blockchains if you really don't like the monetary applications.
As a side note, though, I'm kind of amused and baffled that the Grand Nagus of all people is dismissing any monetary uses for cryptocurrency.