Why do we care about biodiversity?

Seems obvious that we should care. There are intrinsic and practical reasons. Practical reasons are all of the form "biodiversity is good for/as _______" and then you substitute your preferred reason. Popular ones are environmental services, medicinal products, spiritual values, water management... The problem with this very valid approach is that services may be "replaceable." This is, if we discover ways of producing pharmaceuticals without plants, then we do not have a reason to conserve biodiversity.

We do need the pragmatic reasons, but the key idea to conserve biodiversity is, "we value biodiversity for itself" No reasons needed. We care because. Full stop. When in Mexico we ask an average person if she cares about polar bears starving in Greenland, the universal answer is yes. The fate of polar bears matters to the average citizen of Mexico City. Why? Because life is good in general, not because polar bears contribute to the economy of Mexico City. Indeed, people are more concerned about mammals and birds than about ants and gnats, but nevertheless, in the world there is an increasing trend towards more benevolence towards the living, and we see this as the right thing. This is because it looks as if we become better humans when we care about non-humans! We do care about biodiversity because of its huge variety of services, yes, but we fundamentally care about it because it is, it exists, it is good. No more explanation needed.

Thus, the question would be, are the practical reasons the only good ones? When arguing with a politician, or a banker, or an economist, use only the "services" argument?