Should Steem be giving free Steem to those who don't engage in proof-of-brain?

You can say the same thing about all the 'free steem' that is being given out to whales and the people they vote for under the n^2 system.

Should Steem give the biggest advantage to those who don't engage in proof-of-brain?

I don't know what is being compared here, and who has an advantage over who in the context of the question.

Have you read "Evil Whale"?

Yes, it was written in the context of a reduction in curation rewards, and explained the theory of how good voting and curation was incentivized through the existing voting/rewards structure. There are parts of it that are flawed when trying to use the same analysis in the context of linear vs. n^2 curation rewards, and there are also some things that we have learned since the post was written (two years ago) which were the reason the new hardfork was made to change away from n^2. There are a lot of good and valid points in the post.