(Quick note: I only played Ocarina of Time and Majora's Mask for Legend of Zelda, so if gameplay has changed significantly since then I apologize in advance).
Legend of Zelda
In Legend of Zelda, you control a character named Link who has access to a bunch of different equipment. Two staples are a sword and shield combo and a bow and arrows.
The bow and arrows are extremely powerful - they deal a lot of damage from distance (more than the sword, I believe), can pierce through tougher foes (spiders that normally have to be hit in their vulnerable belly can just be one shot anywhere with an arrow), and keep Link well away from danger. There's a major drawback, though - you have limited ammunition. The default typically was 30 arrows (and you can fire an arrow every second) which could be upgraded to 40 or 50 arrows with quests.
Ammunition wasn't easy to acquire, either. Sometimes you could buy them from a store, but that meant leaving the dungeon and returning. Sometimes you'd find a cache of them from destroying objects, but it wasn't a guaranteed source by any means. In short, you used arrows sparingly in situations where you really needed them. They were a trump card, an ace in the hole - not something to be casually spent.
The sword and shield, however, were unlimited in use. They were your default form of gameplay. Situations where you DIDN'T use the sword and shield were unusual. Thus, situations where you could go wild with arrows were extremely fun because you got to be brokenly overpowered for a short amount of time if you were smart about it (like if you knew more arrows were available soon or something).
So the paradigm was to use the sword and shield as your default attack and pull out the bow in special situations to unleash the fury.
Mechwarrior 4: Mercenaries
First of all, Mechwarrior 4: Mercenaries is an awesome game. The Mechwarrior universe revolves around Battlemechs - giant war robots that you pilot around in missions doing anything from assaulting an enemy stronghold to defending factories against aggressors to raiding convoys to ritual combat in a duel-like fashion and more.
My guess that you probably aren't playing this game right now. Which is incredibly stupid, because you should be playing it. Best of all, it was released for free in the last few years, here's a current location where you can download it: Click Me
Note: you'll want to use a joystick to get the most out of the game, though I suppose it might be playable without one. But why would you want to do that?
But I did have a point. In Mechwarrior 4: Mercenaries, there are three main types of weapons: missile, ballistic, and energy.
Missile weapons typically do very high damage for their weight at the cost of limited ammunition. You can slap a missile pack onto a Battlemech when you only have a few tons to spare and you want some extra firepower fairly easily.
Energy weapons have unlimited uses but produce large amounts of heat. If your Battlemech gets too hot it will overheat and shut down, so you can't use too many energy weapons.
In short, you can use energy weapons on weaker targets, fire up the ballistics as well for more difficult enemies, and launch your missiles on top of those when it gets really hairy. If you launch missiles at every weak enemy you see you're going to run out extremely quickly. There are tradeoffs between the different types of attacks and you use the weapons appropriate to the situation.
World of Warcraft
Now let's look at World of Warcraft - specifically from the viewpoint of a Hunter. Let's try a Legend of Zelda approach first...
An enemy approaches! Do you
A: charge into melee with a weapon to conserve your ammunition
B: shoot it
Hint: the answer is B. In fact, the answer is NEVER A. There is no reason for a Hunter to EVER attempt to melee an enemy instead of shooting it and players who did so were relentlessly mocked.
A: Use just your attacks with unlimited uses because it's a weak enemy
B: Use most of your attacks while conserving the strongest ones with limited uses because it's a medium enemy
C: Use all of the attacks available, spending ammunition like water because that's a tough mother that needs to be dropped fast
...wait a second, that doesn't even make sense for a Hunter. ALL of a hunter's attacks require the exact same ammunition. The analogy in this case would be better suited for cooldown usage.
So we've established two important facts:
1. A hunter ALWAYS shoots his enemies
2. All of a hunter's shots require ammunition
Now let's add in an additional fact - unlike Legend of Zelda or Mechwarrior 4: Mercenaries where your ammunition is definitely very limited and needs to be used wisely, Hunters often stock up on thousands of arrows/bullets/etc. In fact, while you're in a raid or dungeon, you don't even notice you are using ammunition unless you run low before you got to restock.
Throw Away Those Rose-Tinted Goggles
So why, then, are some people obsessed over the removal of ammunition in World of Warcraft? It served no useful purpose - you simply brought several thousand to a raid and forgot about it for a few hours. There was no decision making process. Nor was it intended as punishment like durability loss and needing to repair. It wasn't even immersive - people don't carry thousands of arrows in a quiver in stacks of 200.
There's a reason ammunition was removed. It was pointless. Let's get rid of our nostalgia goggles and stop lamenting the loss of ammunition in WoW.