I'm not particularly convinced this is true. It's very likely the case that if some commanding mandate came from the community requesting Jimbo step down that he would, but I don't think the mere act of saying it would make it so. Jimbo compares his role of QEII on occasion, and it's definitely the case that in at least some of the countries where she's Queen, she can only de jure be removed from her position with her permission.
What de jure power does Jimbo have at the moment? His power is purely de facto, so a de facto removal is all that's required. Wikipedia runs of consensus, it doesn't run on rules imposed from on high (expect for a few specific things like NPOV, non-free content, etc).
As for how you remove the queen without her permission - it's called a rebellion and they happen all the time. If the law doesn't let you do what you want, you make a new law and if you're the one with troops on the ground (and the popular support, ideally), that law is the one that matters.
That said, I think you'd be hard pressed to round up much support for petitioning Jimbo to relinquish that authority to the community. But do feel free to open a discussion.
At the moment, I agree. There have been various scandals involving Jimbo lately, but I don't think many Wikipedians believe a word of it (I certainly don't), so I doubt many people would see much point in removing him from power. It is possible that things will change in time - already Jimbo's opinion doesn't always match community consensus, and as consensus changes (or Jimbo's opinion changes), that gap may widen to the point where people don't consider it appropriate for him to have such power.