When it comes down to fixed date ranges for upvoting/commenting, this could actually lead to economical disadvantages. I guess right now you vote when you see a great post or you wait a few minutes before you vote it if it is really fresh and you want more curation rewards.
If you limit yourself to certain times, you therefore will either miss out on curation rewards or you will upvote worse content just because you still will focus on curation rewards.
I guess both things are neither good for you or the network (which incase also is bad for you longterm).
So while I agree that f.e. creating content can be organized better - I wouldn't say it's easy to use the same approach with voting!
Greets,
Martin
that is a very valid point I have not really thought about