No, actually, it isn't. You're quoting a piece of marketing material for chrissake. They handle 80% of all Bitcoin TRADE. As in Bitcoin-to-USD-and-vice-versa trades. Not Bitcoin-to-Bitcoin transactions.

You clearly don't have even a basic understanding of how Bitcoin itself works. It's a distributed, peer-to-peer system. That statement is analogous to saying "The Pirate Bay handles over 80% of all Bittorrent traffic." In reality, TPB handles exactly zero actual torrent traffic, and Gox is in no way involved in processing actual bitcoin blockchain transactions.

Like TBP, Gox is a convenient target for people trying to disrupt easy entry into the more robust distributed system that it provides access to. But if you already have bitcoins and simply wish to spend them, Gox could get sucked into a blackhole and it wouldn't affect you any more than a raid on TBP affects your in-progress torrent downloads.