Is there a reason behind long dps ques?

[Lumivyory]

Not just MMOs. It's literally every game that has roles. MOBAs aren't much different in that regard - the players favor the roles that bring the hurt and do the killing, not the supportive ones. Unless the supportive ones are better at killing than the designated killers, I've seen that happen once or twice as well >_>
But that's really the only exception I ever witnessed. Otherwise, killing roles pretty much > everything else as far as popularity goes.

Same with shooter games like Overwatch, for example
TFW you get into a competitive match and people pick 4 dps and refuse to switch... Sigh

This isn't complete correct. This includes all all unlocked classes and jobs, even if they are not played.

I suppose but far not everyone has all their jobs at level 70, just their mains and a couple of others so the level 70 one is more or less correct

[Risvertasashi]

I've been recently trying to level some dps classes of mine, but i've noticed the wait times are insanely long, as a tank main i think the wait times are a bit much.

Yeah, I've run into the issue when I play around on DPS alt classes too. Solution is to use PotD. Not ideal, but them's the breaks.

Same with shooter games like Overwatch, for example
TFW you get into a competitive match and people pick 4 dps and refuse to switch... Sigh

Well, OW has their LFG system - allowing you to trade time in exchange for a balanced composition. But uh... then you're basically back to MMO-esque queue times.

[Heliantheae]

Overwatch is crazy with their class system. I found my main out of spite. I'm one of those people who likes to set back and play support. But after awhile you do get fed up of seeing people instalock Hanzo and Widow on attack. So I started picked Ana so the "TOO MANY SNIPERS" would be bright red and flashing. Didn't work, but I got somewhat decent at Ana. Anywho, the point is, even in team play a lot of people just want to be number 1. They want to have the top DPS or elim and pick the DPS classes/heroes. And the more people playing them, the longer the queue for them is.

[Lubu_Mykono]

1. 60% of job are DPS. therefore less healers and tanks.
2. Healers and tanks have more responsibility so less people want to play them in casual content
3. Tanks especially play very similar to one another, compared to the Melee Vs Ranged Vs Caster so it can get boring.
4. SCH doesn't need to be levelled if you played Summoner so on average its 3 tanks, 2.5 healers and 8.5 DPS so do the Maths.
5. Developers have said adding DRK and AST a healer and tank didn't change the percent people played those roles that much long-term so behaviours don't change.

So just try and do other things while levelling DPS.
1. PvP
2. Heaven on High or Palace of the Dead
3. Leves (If you are stuck with them and waiting in queues)
4. FATES (same as 3.)

Don't forget food, fc bonus etc and any other bonuses to help like the xp boost from certain items.

[MisterSpamtastic]

at lower levels i did leves and fates while waiting to que, once i started unlocking beast tribes and daily hunts i would work on those. could usually run all my roulettes before i finished. if not, a few minutes in the gold saucer or crafting/gathering would take up the rest of the time.