bitcoin without altcoins is just like dollar without poundsterling, euro, or anything else.
to trade a commodity, we need an alternate to compare the quality (price) when it flooring on the market.
+1, they helped each other, inclduing money exchanging, and altcoins are faster than bitcoin, some smart contracts are used in real life.
i agree that some of them are useful, since they have a different aim and goal then bitcoin. but i do not thing we need them to compare the quality (price).
imagine the whole world would use just one currency. it would be a lot easier and you could still have different prices for food in different regions of the world.