And it's still not terribly difficult at all to hit, even with increased sway. In the situation given after all, didn't they just meet each other after sprinting into each other around a corner by surprise?
So they're both completely in the open to one another at very close range- no concealment. They'd have to be at least 100m or so away for it to be terribly difficult to pull off that shot (hardly "drop-shotting" at such distances anyways.), plus the guy who does not prone easily has time to completely aim his shot and have a tea while the other is still going to prone. 2 fairly well aimed shots is easily allowed, even 3 if somewhat spammed (though still correcting). Considering how easy it is to get the kill on the first shot, it would seem in theory drop-shotting is a complete non-issue.
Funnily enough, practice proves theory. I've never been drop-shotted in ROHOS.
if we're talking practice proving theory, I've dropshotted tons of people with various weapons, from the ptrs (where dropshotting is your only option if you're moving with it out) to the MG (super-effective).