A lot of you are missing some really basic points when it comes to this topic.
1) How much enmity you generate PLD vs MRD is irrelevant. The only thing that matters is if you generate more hate than the DDs. Both tanks can do this well with all current content.
2) Survivability is also irrelevant. As long as you never drop below 1 hp you've survived as much as is necessary. Again btoth tanks can do this.
3) Speed actually makes most fights safer. It reduces the odds of the boss spamming hard hitting AOE attacks that can potentially cause wipes, number of time spawned adds, and allows your best DDs (MNK and BLM) to put up higher dps by finishing the fight before they run out of mp. This area is why War has such a big advantage.

Add to that the fact that a WAR actually becomes better as a tank the more damage they do through both hate management and self healing under Rampage and maybe you can understand why people might want some drastic changes.