what will be the main stat for Rogue/Ninja?

[Alistaire]

No, offtanks are also there to get adds etc. I know plenty of reports from warriors in SCoB that state the things they tank don't require VIT spec in the slightest. But a DPS would have neither the threat generation nor the defense to do their job.

And your point about MNK/DRG both lotting STR accessories in SCoB is also irrelevant, as greed parties are as common if not more so than need parties.