Of the three changes in the EIP the free downvotes allocation is by far the most powerful and the only one that really has the potential to move the dial on behaviour significantly.
I would agree that there is the potential for issues, in particular an increase in toxicity and account targeting, as well as problems with cheap purchased downvotes, and I would have liked to have seen a lot more work on how such issues could be worked around.
But something does need to change. The economy of the content side of Steem is broken. Downvotes are worth the experiment in my view.