I think the role of a search engine is to index the page, and to help users find what they're looking for. It's a difficult task that requires somehow quantifying relevance of answers for a given text string.

Whatever quantification is used is an implicit kind of 'censorship', and the 'relevance' of results for a given string is inherently a value-judgement. That's where the value of a search engine comes from. We choose search engines based off how good its value judgements are.

So, I wish DDG released more details here, because this announcement otherwise just sounds like standard practice. Abusing "quirks in the algorithm" is just called SEO, and it's been a cat-and-mouse battle between search-engines and abuse. Without details, it's harder to interpret this move generously.