Crap coins are needed, they do help spreading the hashing power around, keeping "good" coins  profitable to mine.

It's true that it takes the investors BTCs too, but that will stop soon, the price of the most new altcoins are falling like stone now, burned up investors will think twice before jumping the ship next time.

What's need is some of sort of criteria to classify the coins. Thinks like: technical innovation, developers activity, size of community, merchants adoption, market cap and so on, should be counted into some sort of index. None can't stop crap coming, but an "crap coin indicator" like that would make a difference. Devs of the coin will have to work hard to make it look better, just a "good coin name" won't be enough anymore.