Flaws = Hardness?

I'm playing Ninja Gaiden Sigma, not this original so correct me if the game differs on what I have to say.

Now there's no doubt that this game is harder than the average contemporary game. However I believe there's a couple of flaws which make the game unfairly cheap, rather than hard.

1. Respawns

The enemies re-spawn constantly and instantly. I'm talking about empty an area, pop around a corner, and come back. They've re-spawned. Also you can clear an area around a save point, clear it, and save your game. If you quit and return back to the save point, the enemies return too.

2. Camera

It's a flawed camera. Quite often enemies will attack you quickly from around a corner, or you'll be fighting in a large area and trying to dodge enemies who are behind you. Extremely annoying to be killed due to the fact you can't see the enemy rather than your skill.

3. Controls in relation to potions

In sigma, camera is left analog stick, movement is right. You'll be moving constantly to stay alive, and moving the camera to see where the enemies are. Potions are mapped to the d-pad. So if you wanted to use a potion quickly, you'll have to stop either moving your character (getting hit in the process) or stop moving the camera (so you can't see the enemies/where you want to go). This again results in a lot of cheap shots and kills.

So I do believe the game is great, but a lot the hardness comes from the cheap shots achieved by the above flaws.

Thoughts?