Let's bracket the "was the USSR in the right?" question, and let's ask the "how brutal was the Soviet clampdown on these two uprisings?"

• 1956 Hungary: 2000-3000 killed by the USSR
• 1968 Prague: 137 killed by the USSR

How does this compare to clampdowns by NATO countries (excluding the US)?

• Indonesian National Revolution against the Dutch: 100 000 Indonesians killed by the Dutch

• Algerian War of Independence: 250 000 killed by the French (French estimate) - 1.5 Million (Algerian estimate)

• French War against Vietnamese Independence: 200 000 dead

• Portuguese Colonial Wars: 70,000–110,000 civilians killed by Portugal

• Mau Mau Uprising against the UK: "Officially the number of Mau Mau and other rebels killed was 11,000, including 1,090 convicts hanged by the British administration. The Kenya Human Rights Commission has said 90,000 Kenyans were executed, tortured or maimed during the crackdown, and 160,000 were detained in appalling conditions. "

This is a non-exhaustive list with estimates. The actual brutality is not conveyed. The war crimes are often comparable to the Waffen SS.
You get the idea: the colonial powers were incomparably worse.

The biggest irony of our times is blood thirsty liberals who are cheering for as much war as possible running around calling people tankies.

The use of the word "tankie" these days is so over-used it has become synonymous with "left of the DNC." I've even seen Anarchists described as "tankies," it's getting ridiculous. Still, the word "tankie" is most often used by liberals against Marxists, though they won't admit to having an anti-Marxist bias, mostly because they think they agree with Marx generally but are unfamiliar with Marxist analysis.

Really, more people need to read theory before having an opinion on it to avoid speaking past each other. I wrote an introductory reading list for Marxism-Leninism if anyone wants to get a better understanding of Marxism.

nowadays tankie just means someone who shills for china/russia with a communist background

It's always funny to me how the go-to examples of like, "See, they just blindly support anything the regime does!" tend to be relatively minor events after the state in question has considerably chilled out. Like, Stalin and Mao did much worse things compared to Khrushchev/Hungary and Deng/Tienanmen. The problem being, communists are generally willing to criticize things like the Great Leap Forward, because, surprise surprise, we don't just blindly support anything they do. The reason for this is that the word tankie isn't meant to describe someone who blindly supports everything a communist country does, as it's claimed to, but rather, someone who supports anything any communist country does.

The fear Western leftists had that led to the term being coined was that people who had previously been critical of Stalin and Mao would respond positively to the countries moving away from their approach, and so they had to create a label to discredit such people and associate them with the previous leaders. It's one of the reasons Khrushchev's approach was questionable, because no matter how much you try to distance yourself from someone like Stalin and paint yourself as "one of the good ones," you're still never going to appease the Western left that demands absolute perfection, let alone the West in general.

For context: these are the original lines

If you don't have an opinion on it, you might when you learn the fascists were putting chalk marks on the doors of communists and jews