I think a lot, of what he says and does, is due to his location/clients. Trying to think of how to explain...
The majority of his clients, just want the basics of pet care. That is all they can, or are willing to afford.
For many years his hands were tied, because he didn't own the practice. Only so much he COULD say or recommend. He also tends to lean towards conservative. Costly tests may give answers, but.. in the end, if the result will be the same, he doesn't suggest the tests. Or if x amount will save the pet, but it will only live for a short time.
For Lucy being 10 years old and being fed kibble, for so many previous years... "good for her age" is an understandable explanation...from his point of view. It would be an acceptable explanation to 99.9% of his clients. For me... 10 years old is NOT the end of the road. In a non-kibble feeding world, 10 years old is still youngish.
I can TOTALLY understand your friend asking you. When a vet does tell me something... you are the first person that comes to my mind, to ask for a better explanation!!! You "know" me and my pets. You know where my head is at...