You are exaggerating, none of the things you list as bad, are bad. You dont even say why they are bad, just busted or retarded.
Inventory: The game decides to give you a limited inventory and makes it more restrictive than just about any other of its ilk since bullets and consumables no longer stack in single slots. Consumables isnt that out of the ordinary but the bullets is a major pain. Or least it would be if there wasnt a way around to get it which I'll get to. The system is purely there to force backtracking to the room since the developers couldnt really come with anything else particularly compelling to get you to go back. Thus they just use basic functions to to give it some necessary utility. Although the larger reason is they want you to see the lame hauntings so you can use your candles on the room instead of Eileen. Gotta love how lazy the alternate endings work with them being based of simple candle resource management instead of the more involved steps from Silent Hill 1 and 2.
Speaking of Eileen, she's arguably one of the worst escort missions ever conceived. Micromanaging an ai in horror games is pretty tricky to begin with but SH4 doesnt even attempt to make it work. Giving her a weapon is an actual hindrance and she'll randomly just stop following you or run backwards. So the best course of action ends up being just leaving her somewhere and doing as much of the level solo as you can before going back for her. She'll of course take damage while your away which is why you want to hoard your candles to negate it. I dont think I need to explain why running through the same areas from the first of the half game instead of going to new areas is cheap and lazy do I?
The camera is legitimately broken. In the middle of combat it will just swing behind the walls in completely obstructing your view. Then of course when it does use fixed camera angles it loves to put them in cramped spaces with enemies. This would be fine if the game was still using tank controls but since it doesnt you end up ping ponging from one angle to another eating unnecessary damage.
And as for the combat the primary issue, aside from the camera, is the invincible charge attack which pretty much trivializes all of it. This also serves to undercut the inventory system since instead of collecting ammo your better off just going with a melee weapon.
The game has glaring issues regardless of how dead the franchise is.
The basic structure is a complete misfire too. You have a game about a guy trapped in a room and instead of focusing on isolation, intimate horror, atmosphere, puzzle solving, etc. they make it an action focused title with health bars, a wacky chaser, burping monsters, and haunted wheel chairs. It really should have resembled the mansion portion of Eternal Darkness more than anything else.