There are so many different things going on in how judges write. I hope that they can get some _sense_ of security again so that they feel the freedom to be as open-minded as possible in figuring out the cases before them.
Cards on the table at one definite time.
How much the author had to sweat to get there, to the extent it may matter at all, should show up in the results--a ruling written with a measured, judicial temperament.
Even if it's a late-stage draft that's leaked, that comes with its own host of problems.
Imagine a world where drafts are trotted out by lawyers seeking to argue their interpretation of an old opinion. "The Court originally was going to hold something like my opponent suggests, but that bit got deleted, your honor!"
That would be another level of the problem of what we might call "arguing the changelog," using pieces of floor debate transcripts in the legislative history of a statute.
Justice Scalia analogized that to "entering a crowded room at a cocktail party, and looking over the heads of the guests for your friends."
And that's a concern on top of the potential for a chilling effect on the judiciary.
This presumes that the leaker wasn't one of the Justices themselves, when it almost certainly was.
To test what celebrations or outrage would happen in the streets, maybe?
If they are that concerned with public opinion -- which they shouldn't be, but say they are -- I would think that would incentivize even stronger efforts to maintain confidentiality and discretion.
(Maybe you didn't suggest that it was intentional, but an accident. Even then I might wonder why someone would let their guard down on this case. Maybe there was so much more work done on one particular case, people get physically tired, etc.)