I actually don´t think bots are that much of a problem, when the platform grows almost any post could become viral, it could even be from a brand new user.
This is like an exchange disabling its API because they dont think trading or arbitrage bots are fair, in essence trading bots are worse: they take advantage of trading disparities thus preventing humans from doing so.
However, if the developers and the community really feels that upvote bots are bad then post curation rewards could be eliminated in full, setting a time frame wont fix it since people will just set their bots to up-vote popular account´s content after 4 hours.
BTW I created a poll to see what the community thinks of this issue