If I have a fear that the prior poster is going to change their post in some way, I won't waste my time replying to them. This isn't verbal combat, it's an enthusiast forum. If our goal by quoting them is to somehow make sure people stick to what they are saying and not let them edit their words, it might make sense to take a step back to see what our intention in posting really is.
Quoting everyone on the off-chance that they might change their post is in some respects letting them know you don't trust them to keep their post the same if they don't like your followup.