That.
As a Paladin I tend to flash spam whenever there are 4+ mobs, whilst rotating my 'Riot Blade' combo to keep my MP up (this results in low hate gain on many targets, dedicated DPS focussing on one target will easily pull ahead), or I can cycle the RoH combo to split the enmity across 2-3 mobs at a time (higher hate gain, DPS won't pull hate off me unless I'm undergeared), or I can do a little of both - Flash a few times at the start and RoH the main target, then begin to rotate the RoH combo (and the occasional Flash) around the other mobs once the ST DPS trim the herd a bit. A Warrior is a bit better at getting a large lead in AoE hate quickly but they will struggle to sustain that lead for as long - they can only spam Overpower until they get low on TP and they have no means of regenerating the MP from Flashes unless there is a Bard in the party.
It assumes a lot of skill on the part of ST DPS (MNK and DRG, and to a lesser extent BLM) to be able to split and balance their hate properly across multiple mobs (because they'll sure as heck not be following the Tank's marking if they're doing that). And due to those first two jobs being melee and having highly positional weaponskill combos, they actually LOSE a substantial amount of DPS by repeatedly having to target swap.
If I'm in a party with a SMN and a BRD/BLM and you have all loudly declared your lust for carnage, then yes, by all means you can all spam AoEs and I'll run my reflective paladin rear off trying my darnest to keep everything flashed. But if we throw a few ST damage dealers into the mix then I'll start marking targets in order of how I want them killed. I'll still flash occasionally and you're still free to DoT stuff, but if you end up pulling hate on anything other than the lowest-marked target, well...
...well...
...well I'll probably still attempt to pull it off you because I'm just a teeny tiny bit OCD about maintaining proper aggro control.
But technically you could potentially end up tanking it yourself whilst the ST DDs trim the herd and actually follow* the marking order.
And I'd feel slightly less guilty than normal about losing hate because you'd brought it on yourself.
So there.
[*except for those two duty-finder Relic+1 DRGs from WP the other night. Apparently "Real DRGs don't follow orders", and this includes enemy marking orders. Fun times.]