Dragon Ball Super introduced two villains of the same origin and motivations despite being different versions of each other, and despite the end of their story and arc being lackluster, it nevertheless showed an interesting philosophy that challenges everything our characters have fought for since the very beginning. Zamasu and Goku Black are both characters with more philosophical ideals and villainous motivations that range beyond wanting to conquer the universe (Freeza), and destroying the Z-Warriors (Cell). Goku Black and Zamasu both may have had interesting points to their villainy, and their viewpoint on mortals and the plight from what is shown to us as well as how Zamasu descended into his villainous state. The question this brings up, especially to many in the audience that manifested as a meme, is whether Goku Black and Zamasu did nothing wrong. Were they indeed right to feel as if mortals were unchanging creatures and a violently stagnant existence, or were they simply misguided fools who jumped to leaps in logic and conclusions?
Goku Black as a villain made his introduction as an evil force taking the shape of Son Goku, whereas Zamasu in all iterations was a Supreme Kai in-training whose views on mortals changed for the worse. These views are what caused Zamasu to take action to cause the homicidal consequences of all Mortals, all gods in the Dragon Ball Multiverse, and eventually even destroying Future Trunks's Earth in the process. However, their philosophical ideals weren't unfounded despite the skewed evidence. The species of which Zamasu interacted with after Goku's own visit to his own universe allowed for Zamasu's views to change for the worse, but considering everything that has happened in the Dragon Ball Universe and the Frieza Force itself having mortal aliens fighting for expansion of Freeza's empire; Zamasu and Goku Black may have a point.
Zamasu's Ideals
By this point, it is no surprise many are familiar with Zamasu's descent into madness and godhood. However, it bears noticing that the first time we ever see Zamasu in a normal state, he had relatively naive, and misguided concerns as a Supreme Kai in-training under Gowasu. His ideals at the time were that of superiority, but also confusion as to why they had to keep observing the mortals of their universe and never interact with them for their own betterment. Zamasu's response and internalization of Gowasu's response, that being that they can't interfere and only observe and nurture the mortals despite their decisions, is negative due to the fact that it doesn't properly address Zamasu's concern.
Partially because of Gowasu's (debatably) neglectful approach, and Son Goku's own spar against Zamasu, challenging and threatening his ideals; Zamasu grew resentful of the Kami's way of life. Even worse, when exposed to the barbaric race of Babarians, his own radical ideology worsens to that of an extreme that leads him to breaking the rule, via elimination of a mortal that starts his downward spiral towards extreme godhood. From here, his personality radically shifts and the muddled and confused mindset becomes clearer in the eyes of Gowasu. However, Zamasu's clarity is not a sign of good tidings, but rather becomes an omen to his spiral of godkilling, and eventually, his conquest to enact his Zero-Mortal Plan. At the end of the day, Zamasu and Goku Black agreed and had various points about how mortals are destructive, at times barbaric, and sometimes even selfish to their own kind. It's ugly and ungraceful, as Zamasu would say; but does that necessarily mean he was right?
Final Answer
Zamasu and Goku Black may have been right about a few things regarding mortals, but when it comes to their ultimate decision and outlook on mortals being a monstrous race; that's where their ideologies and standards slowly start to lose momentum and credibility. After all, if Zamasu and Goku Black's Zero-Mortal plan is predicated on the justification of the slaughter of innocent mortals, then it falls apart once one sees the actions of Future Trunks, Goku and Vegeta. Despite not being related to the timeline that Future Trunks comes from, Goku and Vegeta agreed to help and fight Goku Black because it would not only be a threat to them, but more importantly because they learn the suffering that innocents have gone through due to this plan. And even more than that, Zamasu's sample data for the Zero-Mortal Plan, as well as his reasoning for doing so and taking control of Goku's Body borders on self-righteousness and madness overall.
Of course, despite all the evidence to show that Zamasu and Goku Black were in the wrong, it's not right to forget that while their ideals were extreme, weren't unfounded or non-existent. If anything, Dragon Ball Super went out of its way in various episodes to show us Zamasu's reasoning and slowly descent into his cruel actions. So it doesn't become unfounded, so much as it is rather a sequence of events the fans understand and can clearly see from point A to point B where it went wrong. Of course, Dragon Ball Super also makes it clear that at the end of the day, as much as the meme states otherwise, Zamasu and Goku Black were indeed wrong all along.
Dragon Ball, Dragon Ball Z, and Dragon Ball Super are available to stream on Crunchyroll.