So why do you think they have grind and have been increasing the amount of grind? I mean, I know you have fun just playing the game, I do too, but they could make stuff unlock faster without it being an issue, but they chose to make most things take a long time, and they've made a lot of changes that make things take even longer to unlock, so they have some form of grind in mind.

I think they have been decreasing the amount of grind. Since Destiny's launch the following has happened or will happen next week:

1. The Cryptarch was changed to only decode engrams to the same color or better.

They also made legendary engrams show up less often, and they made any legendary engrams held at the time become rare engrams, and legendary engrams can still decrypt to just ascendant shards or energy.

2. Ascendant Materials were added as rewards or reward possibilities to story missions.

...and public events

3. Destination Materials (Spinmetal, etc) were added as rewards for bounties and missions
4. Destination Materials are purchasable from venders in bulk at an exchange rate that has been called generous
5. Exotic weapons and armor no longer need hard to obtain Ascendant Materials to upgrade them. Instead their final upgrade bubble requires a single Exotic Shard which can be bought for semi-easily obtained Strange Coins.
6. Exotic weapons will soon level up faster than they did before. (How much faster we do not yet know.)
7. Loot drops for The Dark Below's raid are said to be more intelligent helping ensure you get a better mix of upgrade materials and "fun items" like guns, ships, etc.

If anything that last one encourages grinding.

Anyway you forgot them killing the loot caves, which were grind incarnate, but a popular theory is their popularity made the game look bad, because people thought it was so un-fun that people would rather shoot at defenseless enemies than play it properly, and I know at least one or two people (outside of this forum) that bought into that to some degree.

The only negatives I can think of are:
1. Old Exotics you own need to be upgraded to keep full pace with the absolute highest end enemies and their perk progress is reset when you upgrade them. (For most activities though you old weapons and armor will be unaffected and will be just as useful as ever.)
2. It will be harder to buy Legendary weapons and armor since you will need Crucible or Vanguard commendations that can only be obtained by leveling up your Vanguard or Crucible rankings.

That second one is pretty big.
They also made it so that items from the queen's wrath event couldn't be broken down into ascendant materials, they changed/fixed an easy-ish way (called an exploit by many) of getting strange coins, and they made the Vault of Glass harder and more complicated (which is at least somewhat justified). I'm pretty sure there have been other things they did that encouraged a grindy way of playing, too.

As for why the grind? A lot of reasons:

-Legendary and Exotic weapons and armor taking a long time to upgrade makes you appreciate the upgrades you eventually activate. Guns like Bad Juju, Thorn, and Truth become significantly more awesome once you are able to switch on their signature upgrades. As we saw the other day, many here put a great deal of value in having completed the work needed to upgrade their weapons.

That's why I brought that up the way I did-- the value you place on an item can be, well, important, in a lot of ways, but they could make upgrades noticeably faster without hurting that sense of value by much. Again, I'm not saying they have to or even necessarily that they should, just that making it take longer than is necessary for the desired affect-- appreciation in this case-- is indicative of grind.

-The harder to buy Legendary items will cause people to be more discerning about what they buy, especially with weapons. It will also slow the rate at which you upgrade a legendary item since you can't as easily buy and shard unwanted items. It will likely push people to do more daily heroic story missions since you get a few ascendant items each day by doing them.

Pushing people to do more missions is exactly what I'm talking about, doing missions for a reward instead of just for fun is grinding.

-By limiting the amount of Legendary and Exotic weapons a player can buy it helps promote diversity among Guardians. It magnifies people's likes. If someone kinda likes Scout Rifles but really likes Shotguns they'll likely spent their slowly earned Marks and Commendations on a shotgun. As a result they won't be able to buy a high end Scout Rifle for a while. Other people will make other choices. The end result is you will encounter someone with your favorite gun less often.

This is a valid reason to me. It does still fall under the issue that they could've made things somewhat faster and not affected this sense of affinity.

-As Cody Miller said earlier, wanting to unlock that next perk or buy that next weapon helps keep people playing. If they are still playing when DLC comes out they will be more likely to buy it.

What? but you just said

As usual, I fail to see how that works. Destiny doesn't have a subscription fee. It doesn't display ads on old signs scattered about Humanity's lost cities. It doesn't have micro-transactions that players are encouraged to buy to speed up getting better weapons or armor. The only way Bungie and Activision make more money is if we the players are happy enough to buy DLC or future games. Until then, each player is an active drain of resources (the servers don't power and oversee themselves!) and each unhappy player put off by the grind is both a lost future sale and a chance for word of mouth to decrease other future sales.

so which is it? Is the grind good for Bungie and Activision (in a way you understand) because it gets people to buy DLC, or is it bad for them because makes people quit the game and not buy DLC, or is it good for them because it makes people quit the game and not be so taxing on their servers?