I didn't hear the Denmark team raise a peep about Russia and their human rights record when they were playing there.
Not in the same way, but the danish FA was not happy about it. Maybe it simply has something to do with the actual death toll in Qatar? There wasnt really specifics with Russia, other than you could accuse them of being a terribly run country.
After all, what they mostly aim at with Qatar now is what has direct relation to the World Cup - the corruption has actually never been fully documented, so that would be a wild accusation to throw at Russia without actual documentation.
Edit: also you gotta look at it in perspective - the more bad world cups, the more tension and frustration builds up. Therefore more people/countries speak up now. Thats about being fed up with corruption and sportswashing in the sport, which after all is the FA’s domain.
Then there is the actual military threat as we are almost neighbours to Russia - you can probably claim double standards on an internetforum, but does a small country like Denmark potentially want to start a bigger political debacle with Russia when the goal with them back then was to not do crazy stuff like Ukraine. Surely as a small country you measure your words a littlle more careful against a nation with nuclear missiles pointing at Europe