I think you've effectively conceded the point here. Losing one's job is generally understood to be a catastrophic outcome for people in our society, especially when someone has been doing that job for a long time (and perhaps also doesn't have the educational level to get another job at anything close to the same compensation). It follows that "do X or you're fired" is a form of force or coercion. In fact that's so obvious in general that to narrow the definition of "force" to exclude it seems to be a case of special pleading. Threatening someone with a severe material consequence and then saying "it's not force because it's your choice" isn't an argument most people are going to accept, and I find it interesting that you're resorting to it, because it's surely not the strongest argument for your position.