We already got the best loot at 45 fragments.
We don't get anything from finding dead ghosts, except grimiore.
Who knows, there may be a time gated quest after getting 50 fragments, like kill oryx on heroic regicide after collecting 50 frags to unlock something something...
You make a good point about the ghosts, I didn't think of it that way.
As much as people hate them I wouldn't say no to time gated quest after getting all the fragments.
It's really ordinary looking too. Nothing special about it.
I'm assuming that Bungie is just trolling everyone.
Wouldn't be the first time.
Ty