Call of Duty, Battlefield, Battlefront, Overwatch, Doom, Titanfall, etc. all of these franchises were able to hit 60fps on the same box.
It was very possible for them to do it, if they wanted. Bungie decided, for whatever reason, that it wasn't important.
CoD has been 60fps even on shit hardware back in the day, but had obviously scaled back graphics to do it each time. (Hell, MW3 was 60fps on the Wii)
Battlefield barely reaches 60fps on console
Overwatch has really small arenas and a bunch of walls/vis blockers, you can't see more than maybe 20% of the total map at any one time
Doom is same thing, even original Dooms were careful to not show much of the map at any one time, which is why you've rarely seen open world games done with any Doom/Quake engine
The only platform Titanfall 1 was 60fps on was PC. Even the 360 version ran more stable than the One version (because it had a framerate lock option for 30fps). Also, again, it seems open but it's a bunch of tracks through corridors cleverly designed to make you not aware you're only seeing about ~20% of the map at any one time.
None of the above games also have to worry about loading and out through zones, they load once for everything and that's it.
Destiny is open world, has to stream in areas both ahead of you and in front of you, and your tradeoff in open world is that it's more costly to render any sort of complexity in your scene. GTAV is also 30fps on these consoles and they have even less complexity per scene but they took that tradeoff so you can go in literally any direction at any elevation at any time.
It's just what you gotta deal with on fixed hardware. The more open your world is, the less complexity you can have per scene as you have to be able to stream in the other parts of the world and hold both parts (area you're leaving, and the area you're entering). The less open it is, then you can go all the way up to the red line in either 60fps or 30, but the 60 redline is way lower than 30s. And to get a fixed framerate, you're technically shooting for something uncapped above 30 so that your 30hz update is solid.
As you said, it's a decision Bungie made, but it's not entirely arbitrary. You can't directly compare games, it's apples to gym socks. They would have to scale back per-section complexity, the AI count, even the amount of different armor and guns, to get to 60hz. Would it still be Destiny at that point?...
(and since PC runs at any arbitrary framerate, including 144hz, it's clear bungie has built the engine to be framerate agnostic)