Define a "genuine result" for a search engine that isn't the result of a process that arbitrarily ranks sites by certain metrics? Like it's humans all the way down, you can't escape that search engines are a large scale system representing "what a group of humans thinks the best results are." There's no unbiased algorithms in search, it's all curation.
Pretending that both sides are equal is not always helpful. Bad actors do exist, and pretending that everything is equally indeterminate is a fatally nihilistic and dangerous view. Sometimes we actually can tell when something is a lie, and we should treat it appropriately. For a tool that retrieves genuine results matching a query, that means down-ranking them.
For the purposes of current event queries, disinformation is certainly spam. The purpose of spam is to fool you into doing something you probably wouldn't otherwise do, usually based on false pretenses. Disinformation is the same. The action it promotes is more indirect - it seeks to influence beliefs, and therefore voting patterns and soft power - but it is still spread with a purpose that is disingenuous. It disguises it's true intent and is dangerous to the user. It is effectively spam applied to the domain of politics and current events, and should be treated as spam is. It should not be a valid result in an information retrieval service.
I agree that this ranking could be the start of a slippery slope. But DDG is being transparent, and you can still get to RT if you disagree. This is a good measure for people unfamiliar with Russia news sources and propaganda networks, who are the people most likely to be susceptible to Russian propaganda.
Sometimes it is helpful to read unsubstantiated rumors or speculation because it is notable. For example, the United States recently claimed that a foreign power was targeting its diplomats with a high powered microwave weapon. Substantial evidence was never produced, but American news media reported the story uncritically. I think that much of the reporting on this topic was disinformation or propaganda. At the same time, if I wanted to read about it, I would expect search engines not to make the editorial decision to censor this reporting. Even if it is disinformation, informed people should be aware of these accusations. In this case, I don’t expect the search engine to return the “truth” but rather “what is being said on this topic.”
If users don't like the change in the search engine algorithm (for whatever reason), they'll stop using the search engine. It's not a weird stance to take.
At the very least this HN submission is surfacing search engine competitors like Startpage, Brave, and Kagi.