A reminder that MTGOX originally stood for "Magic The Gathering Online eXchange". When a site designed for trading cards online turns into the world's biggest Bitcoin exchange you better believe there's not going to be an appropriate level of security underneath it.
It doesn't really seem like a dig at the MtG subculture, IMO. It's just natural that a trading card site probably would focus less on security than a financial institution. This has nothing to do with the people or the hobby involved, and more to do with the fact that pretty much nothing needs as much attention to safety as a bank/currency storage.