It's not what I say that I do that counts, it's what I do in the field.

And the only source of information anyone has for that is: well, they could hire a private detective to have me followed.

Those who tip less than me will claim I'm stupid or encouraging an inefficient practice. Those who tip more than me will claim I'm cheap and depriving someone. Either way, the most vehement response to what I tip, or what I claim I tip, isn't from the server. Tipping isn't only and perhaps not even mainly about the interaction between server and me, but the interaction between me and my fellow diners, both real and virtual.