You change the premise of the conversation and then go about proving your point.
What you started with "...movement finishing should not be a deciding factor in picking a watch." is not "I'd like to see objective evidence that Patek is "reducing quality." "
Your statement about movement finishing may be true for most, including myself. (I do know a couple collectors who actually do heavily weigh finishing but I wouldn't say they're the norm) Finishing is, however, at least factor of quality, among other yes. The weight that one puts on it will differ to each person, but the conclusion rings true, its a factor with high-end watches.
What I was pointing to was the original issue than showing Patek has reduced quality. Specifically in finishing, they objectively have.
Now to your point about it being not being a deciding factor, yes indeed, that's usually true. But you weren't addressing my point.