Personally, I love Destiny. I've logged my hundreds of hours since launch. It is "hamburger gaming" at its finest - it won't win any awards, it won't move you to tears, it won't stay in your mind for months, but its just a damn fun game to play. Get a couple of pals, boot up a Strike, and talk and chill as you shoot some cool, varied enemies in an interesting, beautiful sci-fi universe with some of the finest shooter mechanics to ever grace a console. Yes it could be better, but its always been fun for what it is, and Bungie has slowly but surely been improving the fluff surrounding that delicious core over the past few years.
It isn't for everybody though, and that's fine. Destiny for me is like what FIFA, Assassin's Creed, or CoD is to other people - you just buy it every year, not expecting to light to world on fire, but just because its comforting fun.
Also, I understand people who complain about "LOL WHY IS DER DESTINY 1 FOOTAGE HERE HURRR" but obviously I strongly disagree. When I see footage for World of Warcraft: Legion, I see footage that looks the same as a game from 2004. As in "duh," because it IS a game from 2004. Destiny is the same deal. I'm sick of people saying "oh, I'll wait a year and buy the COMPLETE game." Destiny is not a single product you burn through over a weekend. Its something you play constantly for years. You are along on its evolving journey. If you aren't into that type of game and just want a 15 hour shooter campaign, then why on Earth do you even keep up with Destiny content? That's like an MMO-hater constantly going on FFXIV videos and saying how "the game isn't even FINISHED yet, they expect me to pay full price and monthly sub??? Cheap Square Enix ripping us off."
Rather than paying a monthly subscription fee totaling $120 a year, Bungie instead releases the $60 game and a few $20 expansion packs to total to $120 a year. Its just a different model, but the same fundamental idea. If you think its wrong to buy Destiny 2 because it will have expansions, then its equally wrong to have bought World of Warcaft for $60 in 2004 because you could have just waited for Crusade, Lich King, etc down the road and got it cheaper.