I agree with you on one matter: NW melee is easier than Native or cRPG, for the simple reason of attack directions. All the things mentioned before like chambering, holds, feints etc, are also in Native. So all in all, yes, NW is easier to learn and easier to master.
However, you have probably only seen NA players play hence you think you are the best and the melee is piss easy. Go and take a look at EU linebattles, groupfighting tournaments or even 1v1 tournaments. You'll find plenty of people who are way better than the NA players. It says a lot if the best NA meleer came out of the EU community. Not hating on the NA guys here, just stating facts.
To adress your points specifically:
Why do people think this game is competitive and difficult?
Because everything can be thought of as competitive. Following your logic you could say, CS:GO is so easy, considering you can only shoot in 1 direction. I bet the competitive scene there would disagree on that one.
Melee hardly requires skill, for fucks sakes there's only 2 attack directions. My grandpa could be a "pro" at melee and he doesn't even know what a computer is. Bayonet duels are pretty much a test of who does something stupid first
As mentioned earlier, not making a mistake is a skill. That's the reason many tactics in NW melee base on the perception of the enemy player (examples: holds, feints, dolphins, spinning and changing attack direction while the enemy's view is blocked). Baiting the enemy player into a move you want him to do is a valid tactic don't you think?
Also, regimental linebattles are a terrible way of testing the skill of a regiment. From what I've seen, the more you abuse the rules (FOL, not being in a complete line etc.) and the map layouts, the more likely you are to win.
Why are they a bad way of testing it? Go watch any Linebattles of the NWL. There is a strict ruleset where things like FOL are punished. Using slopes and crests to maneuvre your men into cover while they can shoot the exposed enemy seems like a good tactic to me. It requires commanding skill to push the enemy line out of such positions and using them to your own advantage. Yet again I ask you to take a look at how things are done on the EU side, it's a lot different than NA.
I don't play this game anymore, I'm just curious to hear from the le epic melee gods xD about why they think they are the shit for winning at what is the equivalent of the special olympics.
See my points mentioned above. Nice bait though.