Are some gamers simply naive towards the basis of game design?
Destiny's gameplay is repetitive is something Gauss and others have said, the argument I hear to counter this statement is:
Well, in Mario all you do is jump. In Call of Duty, all you do is shoot people. In Star Fox, all you do is shoot ships. In Tetris, all you do is stack.
Using this argument only shows that you lack knowledge or experience in gaming. Seriously.
Mario games are essentially a logical, action puzzle game featuring different challenges until the end. CoD and Battlefield takes you through the story while mixing up gameplay. Ride a tank, race through this jeep, use pistols only, stealth mission, etc. Star Fox  is a rail shooter in which the field is dynamically changing. Bosses also require different strategies to beat. Actual strategies. A puzzle game is logic-based. Saying it's repetitive implies that you're not willing to learn any potential combos and strategies. Most puzzle games are insanely difficult to master.
Let's look at Destiny. All the missions remain the same. You ride your Sparrow to the destination. You kill enemies. You then have your Ghost hack some sort of machinery. Then you fight a wave of monsters and eventually leading up to a boss, while boss summons more monsters periodically.
Now, the enemies aren't any different. You hit their weak spot, which is 90% of the time, in their head, eyeball, or stomach. You shoot and take cover when you're low on health. Your strategy doesn't change, you're literally not doing anything different. There's stuff like the Hydra and Hobgolbin which gives the illusion that it requires "strategy", but waiting until they lower their shield is not a strategy and requires no extra skill.
There's no missions like in CoD/BF in which you have to ride a gunship, or a sneaking mission, or a boat mission, or any other mission that simply doesn't involve whatever the hell you've already done on the first 3 missions.
Other than the sword-fight level, there's no instance in which you needed to change your strategy or do anything different. It's about as mindless as it can be. Similar to Assassin's Creed I and I believe even Gauss would agree that was one of the most repetitive games ever created.
Thank you FlipmanV for your take on this whole thing. Like I have said before I have been having fun playing the game and I will in all likelihood be playing it for a couple weeks before I think I will lose its flare and then will put it down for awhile. This doesn't mean it is a bad game it just means it isn't a great game.
Enjoy your weekend everyone!