I think you might be right if you want to do everything "perfectly".
But while DRG loses their buff, and a big DoT for them when they can't go from behind, and they lose their 10% buff if they don't flank, so they HAVE to dance back and forth for optimal dps, or take a fairly substantial penalty.
Furthermore jumps are stupidly hard to use atm, and the optimal dragoon rotation is extremely tight and unforgiving as well, especially since the bulk of their damage comes from their filler TTT, which if they mess up their rotation and have to rebuff they lose a lot of "raw" dps from TTT.
The ONLY thing monks miss from failing backstab is autocrit bootshine (which you only do half the time), and a tiny 5% crit boost on true strike (which unless you have tons of SS is unusable anyway).
You can literally sit on flank the entire time as monk and have a negligible impact on your dps.
This is actually interesting, because DRG turns into the backstab melee, while monks are the flank melee.
As for losing GL3, you need to be doing an incredibly tight rotation (for example, trying to fit in more ID), which you shouldn't be doing if you know you must detach from boss soon. You will not lose GL3 unless you need to be away from boss for more than 2 GCDs.
"Monk has 3 stances" is actually much MUCH easier than accidentally flubbing a DRG combo, because 1, your stances force you into certain attacks, and 2, you CANNOT fail to apply you buffs (except for dragon kick, the only one you can "flub"), while a DRG, if they suddenly find themselves out of position, loses all their potency AND loses all their buff, completely throwing off their rotation.
If you mess up the monk rotation and your buffs drop, guess what? All your buffs are applied in one DK->TS->Snap/Demolish/Rockbreaker.
You just have to cycle through that once, and all your non GL buffs are applied, then just cycle through it again using whatever you like to get back 3 stacks.
I fail to see a compelling argument that one is harder than the other. If anything, DRG are easier to mess up than a "safe" monk rotation that just does DK->TS->SP/Demolish.
Also none of your DoTs require positioning, and you get 2 filler GCDs per rotation, which means you can refresh fracture/ToD at any time.