Here is my little list of what I think Destiny NEEDS
1.) Matchmaking for Weekly Heroic Strikes / Raids. While this will just cause even more complaining because groups will have members drop out randomly, atleast that complaint will be gone. Lose one immediate complaint, gain a few more long term ones.
2.) More rewarding mission system. The mission as it is right now is a bit too unrewarding. I finished the story at lv. 20 and had really nothing to show for it. None of the equipment I was using had been found during any part of the story. It is pretty cool you get a unique weapon at the end of the story though, that gun is pretty slick. Even better if you beat the story at a very high level as the gun will match with your character level. They could take queues from games like Diablo 2 where you would get low level legendary and set items throughout your initial playthrough of the game. It kept you interested as you never knew when that awesome item would drop but you knew it COULD come. For me, I basically know I'm not getting anything from lv. 1-20. So why bother right?
Usually in these types of games, defeating a boss is something that should feel like it brings reward. Pretty much every game of this style rewards you for defeating bosses. Bosses are the toughest challenge, and should reward you as such. With all the various things this game offers, they wouldn't have to guarantee an Exotic or whatever, but you should definitely get at the very least high level mats for high level boss kills and the like.
3.) Unbalanced reward system. Some things just do not give enough reward. For example, turning in 50 planet specific material. Spinmetal for example, or whatever. Unless you have some sort of farming system mapped out, it takes a pretty good length of time to even gather 50 spinmetal or any other material ( took me days to get my first 50 ). When you turn the item in, you get 25 Vanguard Reputation. You can get that by spending 10 minutes on a few patrols or even a single assassination patrol which takes all of 4 minutes. So there def needs to be some rebalancing on the reward system.
4.) Enemy Level should determine chance % of item drops. The reason you see people farming the opening level of the Moon for example, killing that same group of enemies over and over for 2 hours, is because there is no evidence that killing enemies whom are level 28 is any different drop % wise from killing enemies lv. 10. That should definitely change. Higher level enemies should have much higher drop rates then low level enemies.
5.) Legendary Engrems Should Never Give Blue Item. A legendary Engrem can give materials sure, because those items have value. You can turn those Strange Coins or Motes of Light into Exotics and legendary items. But too often that awesome moment of getting a legendary Engrem drop is met by rage when you are given a truly useless item in return for it.
6.) A little TOO grindy. Yeah the game has its gameplay roots within the MMO world, but Bungie and other companies need to realize that the only reason grinding ever existed in the first place was for players of MMO's to keep playing each month and thus continue to pay that monthly charge. So the developers of those games placed these very long processes for players to receive something valuable or gain a new level or whatever, souly so that player has to keep playing to see what happens next. Games like these and Diablo and such, there is no monthly fee, so there is really no reason to force me to spend 4 hours a day for 4 days to get enough Marks to get a single item, or gather the materials to upgrade said item. Up the amount of materials people get, the amount of marks rewarded for various tasks, the reputation you get, etc. Grinding really doesn't need to exist in this game to this degree.
7.) More Random Events / Events. This is the type of game where, while you are out exploring and running patrols and doing your daily stuff, it is a nice break to receive something unexpected and extraordinary. So pump up the volume on the random events and create more of that type of thing. Create mysterious NPC's you can run into out in the field that give special missions that span planets. Create even more variety for the current Public Events. Right now it seems to be set to Defend Warsat, Eliminate Target or the Devil Walker drops on Earth for you to take down. Can't think of any others ... and can't think of an enemy like the Devil Walker that drops on any other planet so far. Make going out into the wilderness a potential for true adventure where you can get unexpected missions for unexpected rewards.
Everything else will be added through time. We already know this is a 10 year project basically with atleast 3 main games with DLC and expansions in between each. So this will be an incredibly large game when it is all said and done, but those things above can make things a bit more rewarding and fun for the players as they are in the game now.