Though the reason for this was two fold; the "have combat, then rest to regain spells" paradigm wasn't fun in NWN, and NWN had items specifically to buff Monks, like the handwraps that gave you elemental damage, plus you could get silly stats with the Companion Items.
A key design flaw of the Monk is their MAD-ness; once you can get high scores in multiple abilities, plus magic item support, yeah, they really take off.
Of course, lol, a lot of people liked the Monk because they felt the class didn't need magic item support ("they get so many abilities!"), even though they really needed it more than anybody, save for maybe Wild Shape Druids (who could solve one of their big problems by taking a Monk dip!).