This reply on Twitter by "Harry_Dillema" summed up Mr B pretty well:
"Just change CIA operative to CIA parrot and you're ok."
All that bile has a purpose and it is de-platforming and discrediting all the way. What Shane is trying to do to Jimmy is exactly what that cohort wants.

Jimmy's Youtube channel has basically doubled in subscribers every year since 2013. With around 8500 in June of that year, 20,000 in August 2014 and so on, to a healthy 402,000 today. You can bet that he is well up on the CIA/deep state radar and the knives are out to take him down.

This exchange pretty much sums up why Jimmy's star is rising and the likes of Shane B's is falling. While not perfect Jimmy is very careful with fact checking and correct attribution when it matters. Shane seems to think that blather, bullying and distortion will get him by. It won't. Your analysis, Caitlin, is exactly correct, as usual. The real Mother Jones would be horrified that her name is being so badly abused.