I find that Warframe feels really repetitive. With the fact that you don't change gear often (as the article states, you're often stuck with one gun trying to 'level it up') combined with the relatively monotonous enemy types, it just feels like I'm doing the same thing, over and over.
Of course, you can say the same for Destiny, but the increased variety of weapons, enemies, and interactions between them, makes it feel more varied, moment to moment.
The rewards for Destiny's long-term grind are less compelling, but much of that is because it rewards the player much faster than Warframe does. 30 hours into Destiny I already had hundreds of weapons and powers to play with. All of that slows down in the late-game, and some of that is a little disappointing, but it still gives me plenty of reasons to try something new, like a new weapon, subclass, or whatever. And even though the amount of content I can work towards is slimmer, there's still exotics, colours, cosmetics, and weapons I'm missing, that I can seek out.