Separate comment vote power is an interesting idea and is something to ponder.
I think 38% would be too high at the current level of engagement. However, with the separating of the reward pool, it's reasonable to believe that we will see significantly more high-quality comments. Steemit badly needs more readers and commenters, and I think 38% is a good place to start.
Although I agree with the proposal, the funny thing is I get way more engagement on Steemit than I do on other platforms despite lower views. I get comments on pretty much all my posts, even shitty low effort ones. The median for comments per post is on any given day usually 2 (sometimes 1, sometimes 3), the mean hovers around 5. Source: http://steempunks.com/charts
Occasionally a post is trending and stands out for lack of engagement, but generally there are loads of comments on the top posts as well, given that we have merely 1500 active users per day and that probably includes vote bots.
In comparison the vast majority of my tweets go unresponded to despite having been on the platform for years. When I make a reddit post, I'll be lucky if I get any replies.