Or maybe the function should be re-coded that only the OP instead of the previous ones would be quoted.
When you say OP you mean
'OP' Original Post / Original Poster. This could refer to either the user that started the thread or the first post in the thread.
If that's what you mean, I disagree with you because If this was already implemented it means I won't have been able to qoute reply you right?
Qouting shows you're giving a direct response to another reply on thread. replies without quote most times on a thread shows you're responding to the original thread/post. And other times, those type of reply can be confusing as one may not know what you're responding to.
Qouting shouldn't be restricted to OP in fact, qouting the OP isn't necessary unless you're responding to a particular sentence in that OP and qouting the whole OP isn't appropriate.