The image attached portrays the defence of Stalin as a waste of time at best, this is frankly charitable compared to most self proclaimed leftists who think the rehabilitation of Stalin is actively harmful towards our movement.
There are reasons as to why the rehabilitation of Stalin is indeed an important issue and not just some trivial thing that we must halt in order to gain a larger following.
The rehabilitation of Stalin's image is less about the rehabilitation of Stalin as a historical individual and more about defending and upholding Marxism.
Condemning or even refusing to uphold Stalin to at least some extent is equivalent to fighting our enemies on their terms. Why would we let our enemies decide who we should love and hate? There's no reason to allow the historical narrative that our enemies have constructed to be our historical narrative, that's just ideological surrender, may as well become a liberal at that point.
The total slander and demonization of Stalin's image is what leads most people into deviationist tendencies, tendencies which are totally harmless towards the bourgeoisie. It's only logical, if people believe Marxism-Leninism led to practically 1984 in real life, then why would they follow it?
Rather than keeping quiet about the USSR under Stalin, it is our duty to defend this period against the reactionary slander laid upon it. It was the first time in human history that mankind entered the socialist mode of production, and that's something to be cherished.
The early Soviet Union - i.e. Stalin's tenure - was a period fraught with active insurgency, foreign aggression, and a complete lack of industry and infrastructure. In order to consolidate the gains of the Bolsheviks the Soviet government was tasked with the monumental mission of defeating the immediate threats to its authority, developing a modern economy from scratch, and making sure the needs of its people were all being met.
These are struggles that Revolutionary France and the Thirteen Colonies, by comparison, did not have to deal with.
Turning a feudal backwater into a modern, industrial powerhouse capable of sending men into space doesn't happen within the brief span of 30-40 years - especially when contending with famines, terrorists, sanctions, and invasions - without significant displacement or loss of human life. If it had been Lenin instead of Stalin he likely would've done things differently but a large amount of people would've still be displaced or died regardless. If Kerensky had been in charge maybe none of that would've happened, but also none of the development would've happened either and the Nazis would've burnt Moscow to the ground in a single momentous push and WWII would've lasted far longer and would've been far bloodier, with much of Eastern Europe being ethnically cleansed.
It's easy to look at these numbers and say "that's bad", and it certainly is and nobody will deny that. Stalin made mistakes and deserves to be criticized for them. This doesn't mean he was evil incarnate or that his regime's heavy-handedness wasn't necessary. Personally I'm not a fan of Stalin's leadership and I think Lenin would've performed better; but that's a moot point. Stalin was in power, he did what he believed was necessary to preserve the USSR in its infancy, the Party backed him all the way and ultimately history proved him right: the existential threat of the Nazis was defeated entirely because the Soviet Union was able to transform into a modern nation-state in less than 20 years and thereafter went on to become a pioneer in medicine & science while developing an increasing standard of living. It wasn't flawless, of course, but it only existed at all because Stalin was willing to do what he thought was necessary to keep it alive. The very fact he has a legacy to grapple with at all is a testament to his success.
He built a country out of nothing to the benefit of the majority of its people and he did it without colonialism, slavery, or genocide. The death toll was tragic, and much of it likely could have been avoided, but that is a conclusion based on hindsight and relies on information the decision makers at the time simply did not have. If we're going to critique them we should do so fairly within their own context. These weren't the Nazis planning world domination, global war, and international ethnic cleansing here. These were people trying to build the first socialist state in conditions that were very much not ideal and the fact that they succeeded at all is in and of itself impressive.