There is no reason to repeatedly use Fluid Aura in party content with randoms. It's a situational skill, and a fairly disruptive one at that, designed to remove heat from you if the tank is busy or too far away. It's not meant to be used as an interrupt, nor is it necessary to do so because tanks and DPS have their own skills for that and are more than capable of interrupting anything important that needs to be interrupted. Moreover, tanking at its core is role centered around positioning and control. A WHM going around Fluid Aura'ing stuff on cooldown yelling "I'm helping!!! xD" is removing control from the tank and is screwing with mob positioning, which can be very frustrating considering how that's basically their entire job and you're just unnecessarily making it more annoying.
Sure, I might not kick you for it. But if you do it unnecessarily two or three times, and I politely ask you to stop (and explain why it's annoying), and then you go and insist how it's necessary and helpful and just keep on doing it... well, I'm not really enjoying playing with you, so I'm going to leave and get an instant re-queue while you sit in the dungeon waiting for a replacement. But I also wouldn't really fault someone else for wanting to kick you at that point.
