Well,
the reason I would want to get linear is to have some starting point of reference, so that I don’t feel so lost in space. In offline rendering, I start with linear image, and I apply filmic tone mapping to my liking, but I know how did I get there. If I for example use EXR environment map as my background, then at starting point, that map looks exactly like in Photoshop, when I open it. Same goes with pretty much any texture data. Filmic tone mapping is just fine, but not being able to get to linear is what I have problem with.
An example where it causes practical issue is LUTs. I have loads of LUTs that are supposed to be applied onto Linear image, and transform them into some film look. Since I can not get linear, or override filmic with that LUT, basically entire my LUT library becomes invalid. The LUT won’t look the way it was supposed to with another layer of Filmic tonemapping on top of it. And if I go to Show menu in the viewport, and disable tonemapping in the list of postprocessing controls, then it disables the LUT too, since it is too considered a tonemapping feature.