Absolutely agree. What can you hit? You have two options - concede a try or get yellowed and then concede a try.
You have to grab them by the arms and fall backwards, pulling them on top of you.
I discussed this at the start of the season as the probable consequence of the held up rule changes.
It is the only viable defence. You pull them down and a player each side pins them and pulls them over the line, stopping them from scoring, and winning the possession. The only time you don't have to release a player in the tackle is when they are holding the ball and the ball is over the line. The attack cannot risk the pre-engage because of the penalty if they fail to score, so you let the player get to the line, then do this tackle.
It is like a judo defence, except in judo you grab, fall backwards, use their own momentum and get your feet under them and launch them flying over you.