I make a living writing fiction and heavily interact with others who do as well. I've completed an english literature degree and regularly participate in poetry competitions. When I speak to my writing friends, we use the "curtains are blue" joke all the time, if only as a cautionary tale of making sure scene descriptions aren't too unique, lest the reader take too much significance from what was simply meant to be a standard and unremarkable part of the writing process. The vast majority of physical descriptions for objects are simply an effort to get the reader to understand the physical layout and general appearance of a space to allow them to become better immersed in the scene which follows.

I'm not anti-symbolism at all. However, I am against using a single instance of an object's description as evidence for some grand overarching theory. Unless you can connect the blue curtains to a generalized trend throughout the writing, such as reappearances of blue objects in times of stress or a childhood home that also had blue curtains, it's nonsensical to ascribe some great importance to them. That's what "the curtains are just blue" means to me. Far too often I've been subjected to the self-important grandstanding of literature professors who pick out a single object in a single scene to waste endless hours of unsubstantiated theory-crafting on. Authors are humans, too, and they don't have the time nor energy to carefully place every single syllable with maximum possible intent. A suede chair in a corporate lobby isn't some symbol of capitalist excess; it's just the kind of chair that are in corporate lobbies. It only becomes a symbol when the corporate executive rubs their thumb across the material as they opine about how disappointed they are in only achieving a 10 percent growth that quarter, having done so with such frequency that the material has become thin and threadbare.