To expand on one of the points raised - to comprehend the item clear warning, you have to have chat always running and you have to be able to read English. That may pigeon-hole the server into a more narrow scope of returning players.
Not everyone can read English or read it well. Also I know some younger kids (<10 yrs old) can't play on the server because they aren't allowed to have chat open - rules from the parents. I've told these families that item clear makes it more necessary to read chat to catch the reminder, especially if you are engaged in some task at the wrong time.
It's going to be a trade-off of pros and cons. Reduction of lag versus the discussion going on here. I don't like lag, but if an item clear is a known small positive, SharpSerac may have a point to the impact on players being a bigger deal.
A possible compromise: have the item clear only specific things like common minable blocks, and leave the other stuff alone.