To regard downvotes as "normal" has no equivalent in the physical world, nor do I know of other Internet places where such is practiced. That one should not take the displeasure received from other people personally is not wrong. And although this is a mature way of looking at things and being thematized in philosophies or religious practices, there is no such general attitude to Steemit.
I do not know of any common practice where there is an equivalent for a down-vote. If you're rated on amazon or ebay, that's customer satisfaction information, but you won't deduct anything from the purchase price because someone got a bad rating unless it's clear fraud.
An employee who does a bad job will not get anything deducted from his salary at the end of the month, at most he will be criticized and made aware of his mistakes so that he can improve. It makes a difference whether you get something taken away and no matter what amount it is, even if it is only a small amount, the symbolism behind it says that you can take something away from someone because it is up to a judgement. The difference between plagiarism and the attitude that someone has "earned too much" from something is huge. Plagiarism or downloading paid content is illegal and punishable by a fine.
However, Newsteem states that you can vote down content because you don't like how much money someone has made with a post. This is entering a devil's kitchen and if it is actually believed that someone who receives a downvote has the maturity to take it calmly, this is a repression of the reality of humans psyche.
It would indeed be helpful not to care if someone takes something away from you. But in fact we are far from it. It would be like the attitude that someone takes coins or notes out of your wallet just because it works or because a new form of rule has been proclaimed.
The explanation that the upvotes and downvotes received don't really "exist" as long as the 7-day window is still open is a logical explanation, but it doesn't accept the illogicality of humans. Nowhere is there an established habit that a sum expressed in numbers under the article perceived as "my" blog is not already considered "mine". Once the payout amount appears, people consider it "their payout". Any reduction of this amount is a pain for the ego.
Calling such pain "unjustified" negates the strong ego in people and wants to put it in the corner to make it look like an offended child. Any increase in payout is a joy for the ego and it wants "more of it". To achieve that the ego does not hurt when something is reduced, it would have to cause the ego to be completely indifferent to the "more" at the same time. To both the "more" and the "less" the ego would have to behave calmly. Everyone who is able to let go of his ego is at the same time able to do without incentives and at thereby not have the impression of having to sacrifice something.
In order to attain such mental maturity, people must first come to make nothing of the disapproval of others and welcome it as a helpful hint that other people wish them well.
We are generally far from this ideal and it is doubtful that in online groups such an ideal can dominate or be fixed in space-time, as life is constantly changing and new conflict situations are constantly arising. It therefore remains only for each person to do the work with himself personally and not to expect others to show a maturity that one has to work hard for oneself again and again. Another person's reaction can always be such that he or she is not able to bear the responsibility that is expected of him or her. It is already difficult enough to learn to assess this in friendships. Therefore, it would be wise to always take into account the probability that there are lots of vulnerable egos.
Nobody on Steemit - not even in the offline world - can pin himself to the chest to have given up his ego. That everyone knows this about themselves as well as about others is a sign of intelligence, not stupidity or childishness.