You are absolutely right that configurability is a sign of laziness, the opposite of hard work. But removing configurability is _not_ the sign of hard work. Hard work means addressing the interests of all parties, and Mozilla did not do that.
Why do those 2% of users disable JavaScript? It's in reaction to how JavaScript is used: it enables popups, enables distracting advertisements, lets all sorts of companies track me, makes sites load more slowly, etc. For this 2%, these uses are so odious as to outweigh the beneficial uses of JavaScript. So the hard work would be finding a way to distinguish between the user-friendly and user-hostile uses of JavaScript, and just disable the user-hostile ones, so that the interests of both classes of users would be satisfied.
This would not be new: Firefox's popup blocker is enabled by default, which demonstrates that JavaScript is already disabled for a particular use case, because it proved to be annoying to users. Why not take that a step further? If Mozilla wants to force JavaScript on, they should also address the reasons why that 2% of users go out of their way to disable it today. If those 2% say "I used to disable JavaScript, but now I don't have to" then Mozilla will have done their job.