Most Alt coins are completely pointless and just poor replicas of what's already out there with little to no improvement.
The second quotation explains why, very few actually do something new. Most coins are just a slight tweak of BTC or LTC then a new name is given to it.
As long as you can trade across the digital currencies, they're all basically an extension of Bitcoin. Notice how Bitcoin dropped $40 right after Feathercoin moved onto exchanges for trading? Alt currencies are a slick way to dilute Bitcoin.
a lot of ppl mine alt-coin just to trade for BTC, that's true, and sometime that makes more money than mining BITcoin itself, that way ppl hopping around for alt-coin.