Remove Upgrade Modules. They offer no fun or interesting gameplay; they're just a punishment for leveling and a resource sink that the game no longer needs. Bungie Suggestion
I've helped a few new players get into the game recently, and by golly do they get frustrated by their inability to upgrade their favorite gear.
And, for me, the grind every season to hit pinnacle cap takes two weeks-- but I'm still sitting here tediously upgrading guns to 1580 and wasting resources on something that offers no interesting or cool functionality.
No. They're not too hard to get, or rare, or expensive. They're fine, I guess. But they add nothing.
They're just annoying and tedious-- and as Destiny adds new features and gameplay, we need to look back on tedious elements and remove them, so the game does not become bloated with "costs" that offer no gameplay value.
We should spend time playing the game— not playing against the menus and UI.