I thought it was very weird that he writes without an end in mind.
Actually, I think it's much more normal to make things up as you go. Especially in a super open-ended format like television. I mean, the writers may have some concept of where they might like to take it, but most successful writers will tell you that if a story is going well, the characters kind of take over and the story writes itself. It tends to really ruin the story if you come up with a specific ending and then try to force the plot and characters into that.
In fact, I think that's probably what's hurting the story. They get things set in their minds like "we want to copy the plot of The End of the Affair" or "we want the 100th episode to be a royal wedding" or "couple X has to end up together" and then any kind of organic, character driven development suffers. Which is why I find it weird that Safran would pay all this lip service to letting the characters lead the story. It's like he knows in theory how show-running should be done, but then he lets other shit get in the way of doing it right.