If I were to sob about Viking themed games, would that make you rethink them?

Yes, it would.

I can look at Vikings and say "I don't see a problem here", and can play all the Viking-related games I want. I know what bothers me and what doesn't.

But what I can't do is speak for you and say things like "you're not going to be upset about Vikings, because that makes no sense". You will feel how you feel, regardless of what I believe or how I feel about it.

The problem is that you've taken the argument to extremes, assuming that nobody can make games about anything because somebody will always have a problem with something, but it's not the case. If this video were about Maggie having a problem with there being penguin meeples in her copy of New York Zoo (because she had a bad history with penguins or something), you'd be right to point out the absurdity of it. But colonialism goes hand in hand with atrocities; penguins do not. Colonialism is a touchy subject, so designers have to use a gentle touch - in this case, the touch was not gentle enough, and it hurt someone deeply.

Likewise, the Vikings were violent pillagers - some people have a problem with glorifying that, and they're not wrong just because you don't have the same problem with it.