our DoTs hit for about the same as a BLM's spells except for one significant difference: Clipping
IIRC, an astral fire 3 buffed fire 1 hits for 240 potency, a Bio 1 hits for 240 total potency over 18 seconds.
therefore, fire 1 and bio 1 hit for the same amount of damage per cast.
HOWEVER
once bio is up, recasting bio will not add another 240 potency, it simply resets the timer on the DoT, but recasting fire DOES. as such, casting 4 fires results in 960 potency, casting 4 bios results in 360 potency (allowing the DoT to tick once between bios)
(think of it like this, fire + fire = 2*fire, bio + bio = bio + (bio - ticks remaining on old bio))
we don't "not lose DPS from movement", we just aren't penalized quite as extremely, but needing to refresh a DoT quickly becomes PAINFUL when moving, a BLM can make that back up with a few casts, a SMN can only have one instance of a DoT up at a time, so losing possible ticks hurts us just as much as losing a cast of fire1 (and as far as movement goes, SMN's get bio1 and ruin2, ruin 2 does 80 potency. BLMs get scathe, 120 potency with a 1/5 chance of doing 240 potency, as well as thunderhead procs)
for great AoE, that's not completely true, we have great cleavage (heh) but awful AoE, bane only hits a maximum of three enemies, and tri disaster and miasma 2 are pitiful (dat 30 potency/80 potency over 20ish seconds), so whilst we're AMAZING at 2-4 enemies, any more than that and we quickly fall behind, the only other AoE we have are based on the pet and have pairly nasty cooldowns. our level 50 abilities are on a 5 minute cooldown (enkindle, equivalent to flare) and the other is shadowflare (also equivalent to flare, except it happens over 30 seconds instead of 3, and only if EVERY tick happens, and we can only have one up at a time, so nowhere near as much damage as flare > convert > flare > x-ether > flare > transpose, or hell, holy > holy, the only thing it has over those two spells is that it's pretty mana efficient in comparison, and it applies slow)
our battle rez isn't instant cast, it's identical in every way to raise, the instantness is from swiftcast, a THM ability.
so whilst I can't speak for DRG, MNK or BRD, as far as your point about BLM's goes, they are MASSIVELY superior to SMNs in regards to potential damage, especially if theyre lucky, I don't think anything could possibly outdamage a BLM if they managed to get multiple firestarter and thunderhead procs in an astral phase.
as for why people don't complain about SMN, it's because playing one well is pretty difficult, it requires lots of split second decisions to be made since we have a priority list rather than a rotation (plus, being summoners, sometimes DPS isn't everything, eg, in garuda, I'm often asked to stop DPS after a jump, place down a shadowflare, and wait until she releases plumes so I can tri-disaster them (the shadowflare is there to give a little damage to the plumes in case someone AoEs and breaks them), whenever someone dies, I have to stop DPS to rez them, hell, in titan normal mode, I was once told to switch to topaz carbuncle after the tank somehow managed to eat a landslide), alongside micromanaging your pet and cooldowns, and surviving the encounter. And from what people have told me, they end up seeing a lot of bad summoners (using titan inappropriately, not setting pets to obey, managing dots badly, and worst of the lot: no dots, only ruin spam) , so they likely attribute a good summoner to actually being a good summoner, rather than the class being OP.