Unlikely I know but to inject a bit of reasonableness to brogan's previous point, it often happens that one can reply to the latest post that one can see, but in the time one is typing the damn thing up, someone else inserts another post.
The problem then for anyone else then reading through is that (if one obeys the "don't quote the post above" rule) one's post APPEARS to be referring to the one above, but it actually isn't, it's referring to a post some way up the thread.
The only way one can avoid this in busy threads (like hot threads for the current race, quali or FP) is to quote the one immediately above, as you see it, so that one's post makes sense if or when someone sneaks a post in between.
It may turn out that nobody else has posted in between, but at least it still makes sense to everyone (if one has quoted the post to which one is referring).
Couldn't agree more though about the point concerning replying to one specific part of an "article" post - if you want to do that then delete the rest of the quoted post except the specific bit you're replying to. Simples !
Incidentally this is not a hot topic so just on the very unlikely off chance that someone else has posted in between, I'm referring to brogan's post of "yesterday at 14:54"