ARR had two tank spots: One for a player who only played PLD, and one for a versatile player who could switch between WAR and melee dps as required. HW had two tank spots: one for a versatile player who could switch between PLD and DRK as required, and one for a player that only played WAR. Where you place WAR's heyday depends on which one of those player types you were.

HW WAR was mandatory. It made sense to have your WAR pull on most fights due to Unchained. NIN had slashing, but they generally didn't want to put it up. Much like now, HW WAR was a low APM job (25 APM on average compared to NIN and DRK's 45-50) that had bursts of activity every 90 seconds. It also had a fairly sizable dps advantage over the other tanks for fairly minimal effort, although a DRK with good uptime due to smart Plunge usage was more than capable of embarrassing you if you didn't pay attention. From a gameplay perspective, its the main point of interest was that either RI or Vengeance needed to sync up with your burst rotation so that you got an extra stack. So if you were savvy, you tried to find ways to line up your burst windows with points where you were taking damage. You could also irritate your team by forcing them to wait a minute on each pull so that you could do that special opener where you used Infuriate, then extended the timer with Vengeance, and then did your opener, all for the sake of getting one extra Fell Cleave.

That being said, Heavensward was also the nail in the coffin for Inner Beast. I think there was something satisfying in having a defensive ability that actually used a bit of timing. I think the skill highlight in HW was using PLD (of all things) to Sheltron cleaves in A3S in order to stay in Sword Oath. HW WAR was much too saturated with wannabe tanks only just catching on to 2014/2.3-era 'Man-Mode' tanking for it to offer any satisfaction to the savvy player. Good riddance to those good ole days.