I think the more important aspect is that they should always drop something.

The shields, artifacts and class mods in the original Borderlands were components for your character. Even if it wasn't for your current class, you could trade/give it to another player or mule it to another class of your own. The fun came as they always varied in stats and effects and it could take a while to get a really good one.

The mistake in Borderlands 2 was removing the guaranteed drop with a small chance of it being really good, to a small chance of a drop with a random chance of it being good.

There are other issues that also crop up. Are there money and ammo drops? Are they auto-pickup? Do you have to stop and press a button to pickup weapons and components or are they rewards when you turn in missions?

You can take the idea of "everything a player can use" to far though. Diablo III's for example. When Blizzard made the auction houses, they essentially turned all items beyond what you could use into gold. That gold could be spent at the Auction house to get exactly what you want. Great, nothing wasted, every drop puts you on the path to something better. Players time isn't wasted, and everyone is happy right?

And the response to this system? Utter revulsion. Once the game loses that randomness, and that feel of getting a big drop, it becomes work, and filling bars. Diablo's design rests on the foundation of random rewards and operant conditioning, and moving to a system that gives you what you want very quickly undermines that.

Skinner boxes in games walk a fine line, you can easily go to far with randomization and get something really grindy, or you can make things too visible, and it all feels like work.

So I think a better framework for "component" vs. "Item" is "Big significant events at random intervals" or "Lots of regular little events at predictable intervals." This better explains what you are saying and what Insert Credit is saying. One of IC solutions, selecting an item and filling a bar, seems like the worst of all worlds to me.

FWIW, I don't think either system is necessarily good or bad on it's own. It's more how they are used in a complex set of interacting systems. Big random events have the advantage of generating large spikes of enjoyment, but as said they waste time. They also allow more customization etc. They have the downside of playing out more slowly, and players will end up wasting time.

So how does this all apply to destiny? We know a few things.

1. Loot exists, both dropping from enemies and as quest rewards.
2. Crafting exists in game, we aren't sure if it's modifying existing items, or building new ones.
3. Customization plays a large part in the game

Hopefully we'll get more info at E3, but I'm expecting E3 to focus more in the intrinsic, "This is what shooting is like" kind of stuff.

Now, the idiots at Extra credits would have you think that just because the runes aren't immediately valuable, players wouldn't like getting them and that they wouldn't have as much value. But, I can tell you that runes were highly prized, and people felt very good when one dropped.

How can you tell us that? Which people? How good did they feel? How many, and how often? How was the information collected?

I'm not saying EC is right. They may be wrong. But you're making a positive assertion about how D2 worked. How did you quantify your data to reach that conclusion?