My mother in law just passed. I loved her dearly. She had a Steinert spinet. Really a gawd-awful thing. But I made sure it stayed in her apartment, and her husband (who is still alive) will hold on to it. The family was talking about donating it to a school or something. It would not have lasted long...
Frankly, I don't mind junkers going. The good instruments will still survive this. There was a whole lot of junk produced for many years.
A different example: one of the cars I drive is 24 years old, and is in the annals of one of the best cars ever built. I think it may never end up being junked, because even though it is just a car, it has now gone through the dip in depreciating and is actually gaining value again (there is no rust as of date). However, I don't ever wish I'd worked hard in preserving my parent's VW Dasher, or my friend's Pinto.
I always thought mass produced pianos had no value upon rebuild. That included Japanese names such as Kawai and Yamaha. Yet now I own a rebuilt 1970 C7 Yamaha, and I have learned. I have owned, though, at least two (of my six pianos in my life) that I know would be better off being junked.
An economist by trade is speaking...