I agree that curation rewards for comments should remain.
Regarding the segregation of content types, I think it could make sense to separate reward streams for top-level posts versus comments since there is a distinction made between the two at the blockchain level (the payout times for comments is entirely driven by the payout time for the root post). So this blockchain difference means that comments (posts with depth level greater than 0) should really just be used as commentary on top-level posts rather than other purposes, and so their visibility is expected to be very different than top-level posts that it can perhaps justify a segregated reward stream. (By the way, this proposed hard fork is a good time to finally get rid of the 4 post limit on full payouts. Then posts can be used for microblogging without limitations, and we don't need hacks like using comments on unrelated root posts for microblogs.)
But like you, I don't really like further hard-coded segregation of content types, such as the one between "original content" posts and "link" posts. I think those should just come from the same reward stream. However, I do see value in different types of content having a different percentage of the payout allocated to the post going to author rewards versus curation rewards. People are willing to reward the author of original content more than just a shared link. In fact, in the case of the shared link, the author of the post is really more like just another curator, so perhaps what would be ideal is to distribute all (or nearly all) of the payout to the curators for shared link posts (and the author would of course be the first curator). For original content, the author deserves a large fraction of the payout, but they should still give some fraction of it to curators to keep sufficient motivation for curators to upvote the post in the first place.
So, I suggest that the only segregation of reward streams be between posts versus comments, but to furthermore allow the author of a post/comment to specify the percentage of the payout that goes to the author (with a hardcoded maximum allowable percentage of say 80%) and the rest going to the curators. This percentage would be visible on the post so that it can inform the decision making of curators. And once again, get rid of the 4 post limit.
This does not make a lot of sense to me. Maybe I'm misunderstanding it.
I somewhat like the idea of allowing a variable split, except for the issue of cognitive load. Display of it should probably be some sort of advanced/optional feature. People who are just voting for what they like and not trying to be professional curators should not be pressured to care about curation reward details with visual clutter. Either way that's not a blockchain issue though.
Absolutely 1000% agree with getting rid of the 4 post limit.
My mistake. I meant to write 80% (as in minimum 20% goes to curators). I fixed my post now. Does it make sense now?
Yes, I worry about the cognitive load too. Perhaps displaying it by default isn't so important because of the minimum going to the curators. Perhaps by default it could just use some icon to indicate whether: curators get the hardcoded minimum percentage of payout for this post; curators get 100% of the payout for this post; or, custom payout for curators (hover over icon to see detailed percentage).
I think I like the idea of 3 separated pool rewards. At least 2 separated pool for posts and comments the way @arhag propose really seems to make a lot of sense. I'll be awaiting more tinkering, details and comments to make a better opinion of those proposals.
Also I'm not sure I understand the statement below. If comments don't have curation rewards then what will be the incentives to vote for those comments?
What @smooth said is a no brainer in my opinion.