Are paladins the support tanks of the game?

[Saeno]

Yes and no. All tanks in this game have support and any class in this game that has any kind of support is expected to use them. The reason why PLD's are expected to not pull is because out of the 3 tanks, PLD's take the biggest hit to their DPS and the aggro they create for their DPS loss is not worth it. If PLD didn't suffer a DPS loss from pulling, you can bet PLD would be the premier pulling tank (MT).

One thing to note about FFXIV tanking is that you are expected to DPS a lot more than WoW. You balance defensive responsibilities with your co-tank to ensure that you guys aren't dying but still dishing out high damage.

[Khalithar]

I've full cleared all the current savage stuff this tier and last tier and I can tell you that yes we are the support tank right now. Cover + tempered will to bypass certain mechanics (train ghosts, hyperdrive on god, knockback on graven image/guardian, etc.), Divine Veil, Intervention, the way certain mechanics line up with Hallowed, and I could go on. Right now, Paladin is just too good in the OT spot with the current fight mechanics and because Paladin loses more dps than warrior the way the openers work, you'll basically be OT/support most of the time.

You balance defensive responsibilities with your co-tank to ensure that you guys aren't dying but still dishing out high damage.

I also want to address this because, while Saeno is absolutely correct, I want to elaborate a bit more. Tank damage on bosses in this game tends to come in waves with the big stuff happening at preset and very predictable intervals, as a result once you learn the fights it's really all about pushing your dps as high as possible while remembering to pop the appropriate cooldowns.