I main healer and have a dps @60 as well, just now taking DRK up to 60 (I had PLD stuck at 50). Spending some time in the lowbie dungeons I think one of the main issues is that synched down players are playing their dps roles just as they would in expert: i.e. putting out as much dmg as possible without regard for the enmity meter since it doesn't matter at high level, usually. If a new tank comes into this type of player in Sastasha, Tam Tara, Halatali, etc., they are likely to have to fight more with the enmity of their party mates than the mobs/bosses, as others have mentioned.
I don't think the problem is enmity modifiers or such (though PLD could use just a tad more, maybe) -- I think the real issue lies with the party not playing the dungeon with a mind towards helping the tank. Instead of going all out because you think you're not being a proper dps if you don't put up the highest dps you can, why not look at the enmity meter next to the mobs and if you see yourself close to taking aggro, attempt to change target, use an enmity lowering skill, or something similar? We know that if you take aggro and will kill the mob in the next second or 2 it doesn't matter, but taking and keeping aggro will always be detrimental to new tanks who are trying their best. Sure, getting a little provoke practice in is all good now and then, but the way the starting dungeons are made, and the parties I've had with new tanks there as both healer and dps (and tanking them myself), the enmity "problem" is more to do with people not caring about how they are making the experience for the tank who is struggling to learn and/or even just hold hate.
As Aethys said above -- this kind of thing just turns people off from tanking and is one of the major reason there is always such a shortage. Who wants to always have an uphill battle in a dungeon against not just the mobs, but your own party? Of course people will choose the much easier route of dps or even healing instead of having to be responsible for pulling and holding hate vs. overzealous dps or healer spam. People just need to be more mindful in the starting dungeons about their own enmity, and adjust accordingly. Note that this doesn't apply to later and HW dungeons where tanks should hardly, if ever, lose aggro with their tank stance and more skills.