If the world with non-sentient biota were to be destroyed, something of value would be lost. Biota are composed by organs and cells, essentially same as sentient beings. They are different because they cannot feel, but they are experiencing subject of a life, and they exist as different status—alive or dead. When the world were to be destroyed, they gonna lost their lives, extremely basically. This can be viewed as one of their values because when they are alive, they are beneficial to the world as being a component of the ecosystem. Also, to some extent, after they died, their bodies can become fertilizers which nourish the ecosystem, providing nutrients for our biota.
One opposite side might be: they lack the ability of sentience, so when the world collapse, they even cannot feel what the disaster is. No sentience leads to a non-reversing relationship between ecosystem and the biota, for the system flourishes and breeds the biota, but biota could not feel that.