The blog author is... pretty much clueless. Nobody but him is confusing Bitcoins and Amazon Coins, or referring to the latter as crypto-currency. Nobody but him is confused about the difference between the two.
I think there is a less obvious motive behind this article. It's not that BTC promoters think that Amazon Coins are confusing consumers; rather, to them any competing digital currency is a danger to Bitcoin. The only thing that makes a BTC "valuable" is its scarcity. Since only 21 million BTC will ever be mined, that makes every BTC unique and irreplaceable.
But being unique and irreplaceable does not necessarily equate to being valuable. As in all things digital, Bitcoin's own popularity will be its undoing. There are already dozens of competing crypto-currencies out there, many of them little more than BTC clones. If you have BTC, then it is in your best interests to attack the competition in order to preserve the uniqueness of your "investment". Although no one will be confused by the difference between BTC and Amazon Coins, the very use of the word "Coin" dilutes the BTC brand, so to speak.
In fact, I think we may be seeing the opening salvos of a brand recognition war between competing crypto-currencies. If you have BTC to sell, you do not want a potential buyer to consider an alternative currency. Similarly, if you have Dogecoins, Peercoins, or Litecoins, but not Bitcoins, then it will benefit the value of your own stash if you can promote it as a superior alternative to BTC.
It will be an interesting battle that will ultimately wipe out the speculative value of BTC (and all other crypto-currencies), as consumers realize that many, many different currencies exist that behave just like BTC. Ultimately the value of a BTC (or any other crypto-currency) will drop to a level that is more representative of the network processing costs to verify a transaction, rather than any intrinsic value of the coin itself. And when that happens, BTC may actually go more mainstream, as it will no longer be subject to huge day-to-day shifts in value, or market manipulations by get-rich-quick schemers.