It can confuse but it's the absolutely pointless repeating of the post above that I simply can't fathom. Why do people think everyone else wants to read a post, then read it again 1" further down with one more line added to it (and even the added line is often lost into the earlier quoted post).
If there was an option to turn off 'reply with quote' I would have already done it. I rarely even post to explain it's lack of necessity these days, it's quicker to just delete the entire quote and leave the reply. And never once has anyone ever noticed or mentioned I did that to their post...