I have to nod my head with Glitterhands.
I try know how aggro works in the MMOs I play, because knowing is surviving. And I can let a melee class go to town on a monster to a third of its hitpoints before I touch anything on my hotbar as a conjuror - but as I soon as I so much as tap Profundity, the mob is peeled and on me - and my first spell hasn't even finished the animation yet and I certainly haven't done a lick of damage.
Before I say anything else and before some numpty comes along and accuses me of something I'm not doing, let's be clear that I'm not defending the enmity system in its current iteration as perfect, working as intended, or even good.
All I'm saying is that as a damage class, you need to be aware at all times that healing you is at the bottom of a healer's priority list. First is always themselves and/or the tank and if targeting, resources (ie. MP), healer threat, spell cooldowns, or anything else interfere with their ability to heal players performing a damage role, then those damage players need to stop and think about what is more important...doing what it takes to stay alive or doing more damage and expecting that blaming the healer for your untimely demise is going to undo your halted progression because you spend so much time dead.
From the looks of things, barring bugs or other issues creating unintended results, SE has gone the route of giving damage classes a lot of leeway in the damage department or, to look at it differently, tuning the system so that damage itself is not an enormous enmity generator. It makes sense from a playability standpoint, but it puts the onus on tanks to make sure they're focusing their build (and their playstyle) on those things that carry enhanced enmity generation. And prior to rank 20, abilities that carry an explicit enmity component are not in abundance. And of those that are readily available, Gladiator is the only class that has a reliable one. Phalanx can be used after a Gladiator blocks which is the majority of the time they take a physical hit while their shield is up. The other two tank classes get options to increase their enmity but they're not nearly so reliable. Defender offers a buff to enmity generation but only when the user is in Steadfast Stance, which means it only gives the enmity buff to Marauders, and only Marauders who are not moving around. Pugilists get Jarring Strike, but it can only be used after the Pugilist evades an attack. And that's not nearly so often as a Gladiator blocks an attack.
Starting as soon as any tank class can scrounge up 6k or so guild marks, they can start getting into the dedicated tanking abilities, like Heavy Slash for Gladiators that can replace their starter basic attack with one that has an innate enmity boost. If your tank doesn't have the upgraded tanking version of their basic attack, they're going to struggle with enmity.
In the meantime, while tanks are working their way up to the point where they've got the tricks and skills to build enmity effectively, it seems like healers are producing enmity from their heals in a way that seems tuned under the assumption that the tank is going to be building enmity that they can't always build.
Also, and because it's one of my favorite little bits to harp on, a LOT of tanks are still running around thinking that all they need to do in order to be uber is put Taunt and Provoke side by side on their action bar and rotate between the two, filling up the time between cooldowns with whichever juicy bits they think will earn them SP with little/no regard for stamina. It's very difficult right now to determine what is working and what isn't in terms of the way SE has tuned everything because there are just so **** many tanks who have no clue WTF they're doing but have convinced themselves that their way is the right way and if it's not working, it's because SE blew it.
I took Marauder to 10 for Defender and Pugilist to 10 for Taunt and then kind of forgot about tanking altogether while I worked on crafting and gathering classes. Now that I'm back to tanking and doing my part to learn what I can, I've discovered that I'm probably going to want to tack another few ranks onto both Marauder and Pugilist just to round out my Gladiator's TP-based threat ********
And at the end of the day, when it's all said and done, I could still show up to a rank 20 party with a Square Maple Shield and hempen crafting gear and if the party still decided to have me tank and the damage classes get narfed because I can't hold threat with my Light Slash + ABS-ATK rotation, it's still their fault. It's not fair, I'd probably be blacklisted by at least one person before the party was over, and I'd want to seriously rethink my ambitions about being a tank. But none of that matters, because the players behind damage classes who refuse to adjust their strategy in order to stay alive while doing damage have nobody to blame but themselves.