Since the common notion on this thread is for the DM to pick less debilitating monsters, I thought for fun I would just take a look at options. My party is level 12, so I went through the MM for level 12 monsters. Lets see what monsters are available and how frequent debilitating effects are.
Guardian Naga - At will immobilize (save ends), 5/6 recharge area daze. Very debilitating.
Redspawn Fireblecher - No debilitating effects.
Fen Hydra - No debilitating effects.
Fire Archon Emberguard - No debilitating effects.
Flesh Golem - Two daze (save ends) attacks every round, plus extra attacks when bloodied. Extremely debilitating.
Foulspawn Hulk - No debilitating effects.
Stirge Swarm - No debilitating effects.
Adult Green Dragon - Encounter Stun, 5,6 recharge slowing breath - Moderately debilitating.
Dusk Unicorn - No debilitating effects.
Ettin - No debilitating effects.
Lamia - At will daze, 5,6 recharge area stun - Extremely debilitating.
Viscera Devourer - Minor action at will grab - Moderately debilitating.
Wailing Ghost - Recharge 5,6 area push and immobilize - Moderately debilitating.
Feygrove Choker - At will grab, recharge 6 restrain - Moderately debilitating.
Snaketongue Zealot - No debilitating effects.
Troglodyte Warrior - No debilitating effects.
Banshrae Warrior - Recharge 4,5,6 Stun - Very debilitating.
Kuo-toa Marauder - At will removal of weapon (when you attack) - Moderately debilitating (assuming at least one fighter).
Battle Wight Commander - At will immobilized and weakened - Very debilitating.
Githyanki Warrior - Encounter immobilize (save ends) - Minorly debilitating.
Stone Eye Basilik - Aura slow, at will slow (potential immobilize or petrify effect) - Very debilitating.
Umber Hulk - At will minor action area daze - Extremely debilitating.
So based on this limited sample, the DMs choice is more off an "On/Off" switch when it comes to debilitating effects. There are plenty of monsters with no debilitating effects (many of them have ongoing damage effects but those aren't usually annoying to the player). However, once you choose a monster that has debilitating effects, they tend to be frequently cast able (with the exception of the githyanki warrrior, who has a once a fight effect).
Further, we have several monsters in the bunch that you can expect to cripple your party with debilitating effects for much of the fight.