STR is good in its ways. In end-game, unit control is really essential. This means, you must have the right aggroing power to achieve that, which STR provides. For example, I am an iLVL90 PLD(A) pure STR with the same gears with PLD(B) but he has pure VIT. The problem that occurs here is that PLD(B) has weaker unit control because he allot his stats to all VIT. And for my side, I need to control my enmity by not doing my Rage of Halone skill combo, thus reducing the DPS as PLD can offer. Although DPS roles can suffice the damage.

The next problem is, if a DPS party member has higher enmity output than yours, you'll be running around by controlling the aggro. If he gets the aggro, you'll run towards the enemy which makes positioning disrupted.

Even I am stating a PLD as an example, still WAR and PLD has the same role and must be fulfilled right within a party.