Yeah, Mt. Gox definitely caused the scare itself so that everyone would bitch about it, look for and move to alternatives, as well as gain itself widespread negative press coverage.
The attacks are happening because the rewards are great enough to justify the risk of carrying them out. In truth, I think only a small amount of the lag was down to the culprits. Only a short, sharp shock of decline seems to be enough to panic the majority of the community into selling for no good reason - in itself perpetuating a much greater denial of service.
If the value is tanking, its already too late to sell. So next time, if everyone were to just calm down and ride it out, the culprits wouldn't be able to make so much profit.
BB.