Sure, but quite a few employees are at Mozilla for significant periods of time, and (theoretically) Mozilla doesn't have free reign to run the non-profit into the ground by letting marketshare continue to slip away.

Another perspective a friend recently shared with me is that perhaps it is time for Firefox to go the way of Icedove, Mozilla has taken it pretty far, but it is not its main focus even now, and it can be picked up and developed on into the future (not that there haven't been forks already).