Back when this comic was made, GC did both physical and magical damage, so having strength would push more damage. Since they're talking about M, or Masochists, you want to deal as much damage as possible while also damaging yourself more. There's a % based damage return, and a damage return based on damage dealt. If you have less total HP than you will lose more of your bar per GC use and need more healing.
*edit*
Crap, I forgot to click no bump. Sorry... :|
Uh-uh—I ain't gonna lose when it comes to "M"!STR = INT SUPER SUICIDAL "GRAND CROSS" CRUSADER!!That's an "M", indeed! But that "M" is only ranked 2nd in RO!It's a vs-mode Party!!Really hard to read. I think it says 対戦PTキター!!No, I have decided.'Cause We Like ThemYou need not play an "M" job as your first character... "M" = masochist, for those who do not know.High Zeny Burner!!Why do you two have those jobs...?It's a representative of the Gunslingers, a job too complex to be explained in one panel!'Cause they look awesome!!