Because it veers off topic enough to be a distraction rather than contributing to the subject.
Bias, when not influencing factual reporting, is a tangent at best. The bias of the site is obvious, and doesn't change the facts presented.
Now, there was some non essential derision involved in the article, which is far less than ideal, but tone doesn't change that they did report the facts without falsehood.
So, bringing it up in this thread, is off topic enough to merit a down vote. It's like being at a party, hearing a conversation about how to bake bread, and saying "yeah, bread is great and all, but I dislike that bag color of that flour." Great, that's a valid opinion, but why did you bring it up now?
Maybe not a perfect analogy, but that's the idea.
Mind you, it is okay to make a tangent. But it kinda needs to be a bit more meaty, and you have to expect some degree of proverbial eye rolls.