In the past I've used lots of vulgar comments to show my distaste towards recent shooter tropes like a really limited number of weapons, health regeneration and cover mechanics, but now I'd like to be a little more mature and discuss why my problems are objectively bad for the shooter genre, not just my subjective opinion.
First of all: two weapon slots. OK this is a very bad idea; it tainted my enjoyment of stuff like Halo: CE. Why? Because you lose versatility. You find a new weapon! But... why take it when the two weapons you have now are best for taking out enemies at any range? Compare this to something like Serious Sam 3 when you can run through a group of enemies with your shotgun before switching out to your railgun for a few long ranged kills, then take out your rocket launcher to destroy the massive walking mech. With two weapon slots, it's very flow breaking to keep switching out to other weapons to take on the newest obstacle.
Another, more obvious reason is that it's simply more fun to run around with twelve weapons switching between them to your leisure than just using one, then switching to another as your backup.
Moving on; health regeneration. The reason this is a bad idea is that it's just pretty boring to sit down in cover waiting for you to wipe the food colouring out of your eyes. With health packs, its really tense as you dodge the bullets while crawling with coordinated blinking. Trying to reach a health pack can be really exciting (granted, sometimes it can be frustrating knowing that you've got 1 health and yo can't possibly survive), much more so than twiddling your thumbs and sighing as your health magically reappears. I don't even know why regenerating health is used, its not realistic at all, even though realistic shooters love it so much. Also, sitting in cover is really fucking boring. I want to shoot things in a shooter, not wait a couple of seconds or die.
Finally: cover mechanics. Now this can be a cool idea, especially for stealth games or games like S.T.A.L.K.E.R. (boy typing that title is very very annoying) where it fits the atmosphere, but cover based shooters are incredibly ubiquitous and as a result, boooooring. Plus in a first-person cover shooter you can't notice the bloody artwork that so many hours and neglected children were sunk into, except the guy who worked on the ceramic walls I guess. Like I said, cover can work. But in large doses? No. Back in 2007 when I first played Gears of War, I was faintly intrigued by cover based shooting. Then in 2011 beginning Gears of War 3, I was fucking sick of it.
So how should shooters change? Well, they should be more like shooters like Doom, Painkiller, Serious Sam etc. These are really fun games yes, but in the story department not so much. BUT games like that can have really excellent stories. Take my favourite game, Half-Life 2; no health regeneration or cover mechanics, and loads and loads of weapons, but also had a fantastic and dynamic story with a surprisingly well realised setting. So yeah, be more like that.
I just felt like writing something a little more serious today, but anyway. DEVELOPERS: HEED MY WORDS!