Why is criticism of Stalin encouraged while criticism of Churchill is very taboo?

Let me preface my post with this: Stalin is very bad, and there are very many legitimate criticism which can be made against him.

However, I find that on the internet and in many circles the criticisms are often just anti-communist/anti-soviet propaganda which you can literally find in Nazi posters and publications.

Similarly, many criticisms of Churchill are very Nazi-coded and seek to make the axis powers seem more reasonable and less evil.

But, when I see criticism of Stalin, nobody cares and actually I find people responding to it positively and engaging in further criticism (that is often very Nazi-coded). In the same places, if someone makes similar comments about Churchill they're rightly criticized for their Nazi-coded arguments/beliefs.

I don't think Churchill is much better than Stalin, just different/more western. Whereas Stalin oppressed the people in the Soviet Union, Churchill oppressed the hundreds of millions in the British colonies and people have a more favorable view of Colonial oppression?