Alright, here I go:
If by move left and right you mean being able to change course on a dime to the opposite direction you were previously moving and retain all of your speed by defying the laws of physics, then considered yourself mocked.

If you simply mean walking side to side, by which you would likely make yourself look like an idiot if you did so in real life and get yourself killed, then feel free to do so to your hearts content.

Either way, it doesn't really make sense from my point of view to strafe.

Honestly, I haven't played any of the first three games you mentioned, though I have a moderate degree of experience with the second two, and I happen to notice they are immensely popular games, much more so than what I've heard of CS, Halo, or PS. Yes, it is true that sales are not the mark of a great game, but they have to be doing something right to get people to keep coming back.

Hmph, did I say that I stand still? I asked his definition of strafing because different people have different definitions of strafe. Mine is when a person simply moves-quickly or slowly-in a direction perpendicular to the direction they are facing. I do this, though his definition seems to what I call zig-zagging, which, as I said, doesn't make sense to me.

Maybe I haven't made this clear enough. I use cover, I use my definition of strafing, I use what I like to call gungame. It involves using more than a single tactic to win a fight, and your definition of strafing is exactly what my gungame is not: a single tactic. If you can just step side to side to dodge the majority of bullets whilst spraying bullets into your target with perfect accuracy, your "legit tactic" is overpowered.

You people are really making it hard to respond to the massive amount of your hateful and ignorant comments.
-Science fiction, I bolded the part you should look at.
-Super soldiers, look back up at that bolded word.
-Basketball, do you know what a feint is? It's making it look as if you will move in a direction and then moving in the opposite, not building up a massive amount of speed and momentum, then instantly moving in the opposite direction whilst retaining all your speed, that is defying physics.

Are you wondering why I though the fiction part was important even though we are playing a fictitious game? I will go along the lines of another comment I saw once in a different thread:
Though this is fiction, we still are able to fight on the planets because gravity holds us down. We wear dropsuits because we are not immune to bullets. When I run into a wall, I get stopped, because physics say I do, even in this fictitious video game. We are still abiding by physics, and the physics don't add up here.

Strafing VS This

Notice the ridiculous dancing method of strafing which noobs do a lot. Take note on the second video, makes more sense because you actually aim and no mind games like Strafing.

Strafing is used for mind games. Left...right...forward...back...until someone dies. In second video, you take cover, you heal yourself, you aim, you shoot.

Did you read my comment? Your response made no sense at all. Let me simplify what I said before.

I don't like strafing because to both defies the laws of physics and allows people to be uber powerful by using a single tactic. Why use cover when you can just dodge the bullets right? Why get out of the enemies line of sight to recharge your shields when they never get depleted in the first place? Why should accuracy matter when you have all the time in the world to reload and spray a full clip into your enemy again and again because they can't hit you?

I'll even make a TL;DR for you: Strafing is a single tactic, and will outplay complex tactics.
Here's a TL;DR for my TL;DR: Strafing=bad

Your talking about hiding behind a corner like a call of duty fuckboy. That's exactly what this game has devolved into.

Little call of duty camping fuckboys and Battlefield vehicle whores can't handle strafers that's why they buy the same game every year. This game could have been different.

I could be in a militia gear all day with strafing speed back in the game. No need for expensive gear. I can circle around against a heavy suit while I lol'd to his death.