Mtgox survived one or two hacks last summer, they've upped their security probably withstanding more attempts since then than any other bitcoin online business. They're DDOS resistant to capacity that technology allows. They've had backups and were able to rollback their books after last summer's hack. And they were one of the first using cold storage for majority of bitcoins on their exchange. I'd say out of amateur company last year they've grew into one of most if not the most technologically solid bitcoin companies today. Other than deposit/withdraw issues mainly due to interfacing with fiat-ruled world they've upheld their reputation as an exchange on high level.
Bitcoinica on another hand? I've lost count have many times it's been successfully hacked into and stolen from, there was some much fail, negligence, hindsight to security that it is not even comparable with Mtgox. Apples and oranges.
MtGox was also hated by a lot of bitcoiners and some forum thread about mtgox raged for 50+ pages, just like bitcoinica. They also have a meme invented against them. It was called being "goxed".
However, mtgox survives/resolve the crisis, and people move on with their life, and the hatred, if not mistrust, disappears.
Bitcoinica consultancy on the other hand, just utterly fall apart after zhoutong/friend_of_zhoutong stole the money.
Only in crisis do people discover the true strength/weakness of an organization and the characters of the people who run it. If an exchange never been through the baptism of crisis, you don't know their integrity.
(To be fair, mtgox never have their money stolen by a possible insider who seems all trustworthy)