some witnesses have auto-voting bots and this is a GOOD thing since it is not humanely possible to be awake and voting 24 hours a day

This is sugarcoating. Auto-voting bots are not able to recognize quality content. There is no other way currently to recognize quality content other than have it processed by a human brain. What auto-voting bots are doing is voting on content issued by authors who had a good past performance regardless of the relative merit of their content. And since these bots are first in after the content is released, they undercut everyone else. This is the Steem version of HFT trading. Just look at Wang bot. That witnesses that are paid out of the dilution of everyone else's stake partake to this kind of practice is not something to be proud about, and I don't know what to think of the fact you condone it as "a GOOD thing".

Some dolphins follow whales and try to vote just before them, in my opinion that strategy is not adding any value to steemit curation system

That's inconsistent. How can "dolphin" front run whales (voting before is called front running, not following as you said) if Whales voting isn't predictable. Yeah right, whales voting is damn predictable because they vote on maximum payout posts based on historical performance: @stellabelle, @andrarchy, @heiditravels, @dan, @cryptoctopus, @donkeypong etc. These are the "bluechips". Talk about fair retribution of content. If even witnesses and devs aren't showing the right example, don't come crying when Steemit becomes unusable because most of the revenue is extracted using quantitative posting and voting methods centered around technical features of posts.