http://dapps.ethercasts.com looks like a bunch of useless homework projects
That's a pretty endless list with plenty of smart people working hard on various promising projects, that alone tells you why Ethereum has value, because innovation gathers the smartest people possible. Ethereum barely has one year under its belt, its price is based on potential alone.
Bitcoin has more than 5 and we are still quite not sure what it does, now it's digital gold and not a currency any more. Still hasn't catch on either. Both can transfer value quickly (Ethereum quite faster) though, just like many other coins o cryptocurrencies.
To me, the bitcoin is both digital gold and a kind of currency. I invest in the bitcoin and also use it to buy things.
That is what we all should do.
Except it doesn't make sense at all, it's cool of course to be able to buy stuff but what problem solves for the average consumer or company? Nothing. No business can be built on it because of its volatility, it's only used for speculation and hoarding.
Now in the future if businesses would actually use its blockchain (which it is its main value imo) and start adding services, registries, data into it and turning BTC or ETH into a huge database, then the value would be astronomical, every single satoshi or wei could count. A decentralized, bulletproof, globalized database/server.