Favoring emotion over facts while advocating for a cause is still a sugar high of advocacy, regardless of the cause's righteousness. A short burst quickly forgotten, with a chance of discrediting what you're trying to advocate if the facts aren't right.
Even amongst YouTubers, you can favor facts over emotions (without discarding emotion!) and be a more effective advocate who arms others with both motivation and useful, effective knowledge.[1]
I don't follow Rossman very closely but I am familiar with his grumpy, griping style. To be clear, is the claim here that his advocacy work frequently features factual errors, or just that his presentation is too emotive?
Aside: What does "facts over emotion" mean? Aren't facts and emotions orthogonal?
Rossmann is still relevant and to my knowledge has not discredited his cause. Your comment about him needing to get his facts right or risking irrelevance is wishful thinking and clearly not reflective of the reality of his impact on Right to Repair legislation (if you are suggesting that he does not get his facts right).
Technology Connections is an educational channel that occasionally offers political commentary. Telling his audience to vote is a call to action, but not the same as organizing. Rossmann is an organizer who engages with policymakers. To treat them as being on the same level is to misunderstand what they are each doing.