Destiny's core designs have been flawed from the get-go. Destiny is supposed to be a game that you can play with your friends, it's even supposed to be a game elevated by the community at large (the major reason given for that heinous review embargo because reviewers wouldn't experience the game "in the wild" and would then not get the full experience) but the game seems to actively want to prevent playing with friends. Everything in the game (but raids) are limited to 3 players. That means that if your group of friends is 4 or more players, then your group has to be split-up (my group was consistently split up because of this and it sucked). The reason we left the game is actually largely due to this. Bungie didn't make Destiny to be flexible. There was no gametype that would allow for most group sizes (should have been requirements like 3-6 players, etc.). Even exploration, which doesn't really seem like it should require a group size, limits teams to 3 player strikes. This part of the game is just awful, and it put a horrible taste in my mouth since the beginning.
Honestly, Bungie was one of my favorite developers before this game, but I feel like they have been somewhat misleading throughout this entire game's development (you can go to that mountain -- we could go there now, but for the sake of time...., or this game will have a story in the scope of "Star Wars", or the game requires community involvement before you can truly experience it).