However, there are many extensions that won't be possible in the new extension environment and they will die a silent death as they don't have cheerleaders who can force Mozilla to accommodate them in the new webextension plans; I know one or two such extensions myself (don't use them personally, so I may be wrong, may be not). This forced euthanasia of extensions make FF ecosystem poorer, and FF just another Chrome wannabe.
The point is, Mozilla should show the traits of leader; criticism still has merit whether Vimperator work or not.