Sorry Robert, but the use of 'Can' in 5e style-writing is very clear - it's a choice the player has, and it is not automatic or essential.
If I am a rogue and I am standing next to a goblin that has been hit once, knocked prone, but against all odds is still fighting... and the BBEG is *over there*, 20 feet from me, with my ally harassing them in the middle... I want to use my sneak attack on the big guy, not the little goblin. I need to kill the goblin first though, because I don't want to risk an OA while I'm on 3Hp...
So, in standard 5e rules, I can stab the goblin with my attack action, and I can *choose* not to apply sneak attack to the damage there, because I'm confident that my minimum damage will drop it, so that I can then safely move up to the boss and stab them in the back with my bonus action off-hand dagger... and apply my sneak attack to the main target when/if I hit. This is an important player choice value point to the feature, and it's one you'll find in a lot of other class features in other classes as well. If it's something that simply happens and is not a choice, they do not use the word 'can'; this is very much deliberate in the style.
Ideally, we should be able to do this in game as well.
That said, if we have to choose between the current implementation (ick) and having sneak attack add itself to the first legitimate attack that meets its requirements each turn (including other creature's turns), and those are our only two options... then I would prefer the latter, because at least that would be closer to reasonable than the current mess. I definitely want proper control over it, but at this point I'll take any improvement over the current.
Can you cite anywhere where I said it was "automatic"? The damage applies, only if the conditions apply. Those conditions are: Do you have advantage, or, does your target have an ally within 5 feet. If neither of these is met, then you will not get your SA damage. If either one is, including on an AoO, then you will. You do not roll a sneak attack, you roll your normal attack, and apply the damage. In every other parlance, this means that it's passively granted. Something that is granted passively is, by definition, passive. Again, because there are conditions to be met to qualify for SA damage, it says "can", because it's possible that the conditions won't be met, and you won't get the damage.
Now, go ahead and show me where, in the PHB, it says "you must roll a sneak attack to get sneak attack damage. Feel free to copy paste it, but do provide a link to the source.
