She did explicitly state that it can’t be blocked or defended against, but it comes out later that this only means through magical defense of a direct hit. It can be physically deflected - so indirectly defended against. Dumbledore uses magic to move a statue into the way and protect himself and Harry. This was in the fifth book though, so it’s definitely possible she retconned it after criticism

You’re definitely right about it being a poorly-contrived scoring system, but there are a few games in the books where the team lost the game but grabbed the snitch. It’s always described as a “stem the bleeding” type decision

Edit: sorry, now seeing the replies to your other comments saying this, I guess you know by now 😅

I think it’s a joke but this would be a real game changer if so