I agree. In 4e, for instance, there are at least two ways of building a monk-like character: the monk class, and the avenger class.
You can also see this if you look at Monte Cook's Arcana Unearthed/Evolved, in which his monk variant is The Oathsworn.
@Minigiant , @Salamandyr - I think your arguments, if followed through on, will tend to produce "monks" that no one will play. For instance, no one in a typical D&D game is going to build a 10th level fighter but then drop their armour and weapons and fight bare-handed against 5th level monsters. That's unreaslistic except in some pretty niche situations. So for those who want to play someone who fits the Jet Li or Crouching Tiger archetype, we need a class that makes fighting without arms or armour mechanically viable. And it needs to do so from 1st level, much like a paladin or fighter or thief needs to be a viable representation of their basic archetype from 1st level.
The monk would be able to do warrior stuff at 1st level. The real difference is that the unarmed/simpleweapon and unarmored tactic will not be the focus. They would get bonuses to tumbling, jumping, seeing things, and detecting lies.
The only difference is that you are not a Jedi Knight or Jedi Master at level 1. At level 1, a monk is more like a newbie padawan. No slouch but you'll only be able to knock away one thrown spear. Not 11. They are tricksters who can fight. Monks rely on all their learned abilities to fight on level with a warrior with weapon and armor.
This is why the Ki model is great. When they are using Ki they are warrior quality, for even better at fighting than a normal warrior. But when they don't/cant use ki, they are rogues without sneak attack. Much like a rogue with neither an advantage from their tricks and skills nor nearby friends can't fight equal level threats. Or a bard who is out of magic and songs can't fight off the pirates and orcs.