My main issue with that article on ProleWiki lies in its first paragraph:

Authoritarianism is an idealist and loosely defined concept that is often used by liberals (liberalism being the ideology of capitalism) to demonize both past and present socialist states and dismiss any argument in support of these states.

In the very beginning of the article, ProleWIki equated liberalism with capitalism (they are very different), and also claimed them that liberals have "demonized" socialist states with this term. There is no denying that some liberals have demonized socialist states, but I would argue that this term was used properly in that context.

Have you ever noticed the most prominent difference between socialist governments and the governments of the rest of the world? In most socialist countries, you aren't really allowed to publicly criticize the government. Ever noticed how much criticisms of the USA, the UK, France, or really any liberal country floats around the Internet? If you speak Chinese, I kindly ask you to go check out Weibo (Chinese Twitter), try posting something remotely critical of President Xi and watch your post get removed. Or try sending a message to a Chinese citizen with Weixin (Chinese Whatsapp), talk about the protest banner that someone hung on Sitong bridge in Beijing 11 months ago and see how your account gets disabled.

As you can see, the Chinese government exerts a lot more power on censoring Internet speech than the liberal countries do. I am not qualified to say whether the "western" countries are authoritarian, but in comparison, those socialist states really do enforce a lot more rules. Socialist states really are more authoritarian in comparison. It is more than fitting to call them authoritarian.

[that's like saying] “you’re biased, so why should I believe you?” [in a debate]

Now that I think about it, I realize that that was indeed not a good argument. But that was also what another Hexbear user said to dismiss the Wikipedia article just a few parent comments above. They basically said "Wikipedia is biased, so why should I believe Wikipedia?"

BTW sorry for the late reply. I was kind of busy.