They will be required to publish daily for some Merit.
No one is required to post for Merit. If you just want to post randomly throughout the week, then that's fine too. Sure, the chances of you not getting more Merits will shrink a bit, but the main point is that people should be posting naturally, and not for the sake of Merits.
I agree with you will be long posts or useful but generally not useful because they are mandatory shares.
People are forcing and exaggerating in their posts to get Merits, that I have noticed too, but that's still better than spamming with 'yes I think the price will go up', or 'Bitcoin will make us rich, but we have to trust in Bitcoin'. Everything that may potentially enhance the discussion field in a thread is a welcome addition, because that's what's missing now.