I think this is a good idea, but probably not realistic until the next expansion. It would be simple to do (add a hate drop on DPS stance or something), but considering all our new toys are DPS and some are stance-restricted it would make people mad to be forced into tank stance unless they give us new toys for hate generation to keep us interested.
If they dropped this on us now, it would be like being given a toy cardboard sword and then having that sword soaked with water so it's floppy and useless. You'd be more angry than if you never got the toy in the first place!
At the end of the day FFXIV is a theme park where we get to play out the hero of a FF game and feel awesome for a few hours a week. They need to make our toys all feel really important; if they wanted to put us into tank stance, then they've already failed to design it so that cool to do so.
