I agree that the ranked system needs a rework in order to prevent deranking.
I also do not blame players for doing this at all. This is a competitive design problem.

If you create a game in which significant economic gain can be made and just hope that the honor system is going to keep people without thousands of dollars of ETH slamming F2P decks against double demo decks you've made a massive misstep.

It trickles down because you have mediocre players with top cards deranking to Gold. Then you have players that should be able to compete in Gold deranking, and so on and so forth.

I think that the answer here is making ranked a separate queue that you can only queue your matches for the weekend in. Having ranked and non ranked game rating tied together is the root issue here.