I have a Warlock, RDruid, DPriest, FMage, AWarrior and HPaladin at 90. While Monks are more problematic on some classes than others, I find that of all melee Monks have the most:
A) uptime on me (or their target).
B) rooting/slowing ability (ranged root plus permanently slowed via Disable).
C) CC (be it a snare, stun or interrupt).
1) Interrupt that also silences (positional requirement is a small issue with the rest of their toolkit; see Paralysis/Leg Sweep --> Spear Hand Jab from the front).
2) No ranged silence but a ranged root, one melee snare/root, melee Incapacitate and two stuns in melee range (one AoE).
3) Ridiculous mobility (double Roll/Chi Torpedo, Tiger's Lust and aforementioned roots/slows).
1) Interrupt that does not silence.
2) Ranged silence/stun and ranged root.
3) Low mobility but double Death Grip (if used properly) for gap closers and interrupts.
1) Interrupt and no silences but Intimidating Shout acts as a very effective second Interrupt.
2) Warriors have no ranged CC other than Storm Bolt (which is NOT common yet effective).
3) Double Charge option or single charge that stuns for several seconds, "AoE" Shockwave stun and very good mobility with Heroic Leap and Safeguard, not to mention Hamstring and possibly Hindering Strikes glyph/Staggering Shout/Piercing Howl.
1) Garrote is basically an "Interrupt" that silences *especially for Sub* but, for argument's sake, I will say it's just an interrupt.
2) Ranged CC is pretty much non-existent but some gap closers (Sprint, Shadowstep, Burst of Speed).
3) CC is at a max with two stuns and a third off the DR (Paralytic Poison), two Incapacitates and an Interrupt.
I may have missed some CC here but think it's a fairly good analogy. While it may seem that each class is balanced, I argue that Monks are just nuts in uptime when compared to other melee. The most annoying thing I find is that if you get away from them, something is always up: Tiger's Lust, Chi Torpedo or one of their CCs.
NOTE: I am aware that some of the CC I used in this comparison are talents, however, they are mentioned because a large majority of players get said talents/glyphs: