Some people consider failure to be "completely unusable" - others say "if it doesn't repeatably track or return to zero - it's not working as it should - that's failure"
First group - says "my car burns oil, the passenger door only opens from the outside and there's a weird shimmy above 55mph but I get where I'm going and have been for 2 years!"
2nd groups says "it may work but it's still a chunk of chitt, this is better over here...."
For the person who buys a rifle to hunt deer with, a scope behaving imprecisely during zero is of no consequence. That shooter will get it zeroed and never dick with it again. That's not a failure, since the scope serves its purpose of allowing the shooter to kill deer. Then an internet blowhard comes along and insists that scope is a failure despite the fact that it does exactly what the shooter wants it to do.
Return to zero isn't just after an adjustment is made at the caps. It needs to return to zero after recoil.
Ideally - you sight in a rifle once and done. None of these mad rushes the 10 days before season to "make sure it's on" with a couple shots that turns into 6.
Rifles never should lose zero sitting in the cabinet. They lose zero or fail to RTZ after recoil AND turret spinning - should one chose to do so.
It is lost on some people that when comparing two scopes, one with an erector assembly designed and built to move correctly through lots of use (track, RTZ, etc.), and the other that moves erratically due to design and build quality, it is not unreasonable to expect the first to stay put more reliably than the second, as well as moving more reliably.
That's not lost on me at all. That doesn't change my reality that once I have set a scope for a given load, I have never had shifting issues with scopes that have had some mystery in zeroing. I am going to pull my 257 Roberts Ruger Ultralight out of the safe this October and shoot 2, 3 round groups at 100 yards. It is going to give me the same 1 1/2 inch groups that it has for the past 20 years, to the same point of impact with the same load. I may or may not use it during hunting season this year. If I do use it, I will have a one shot kill.
Carry on with whatever works for you. Nobody is trying to change your reality.
The problem is that when you and others state something like “been using 20 Leupolds for 30 years, with no failures,” you’re implying that your Leupolds work as advertised. I would submit that your use/requirements of the scope do not depend on whether or not it works as advertised. Leupold scopes are advertised (whether implicitly or explicitly) as being adjustable in specific increments (whether 1/4 MOA, 0.1 MRAD, etc.), and retaining that erector setting even when subjected to repeated recoil. IMO/IME, an unacceptably high percentage of Leups don’t perform to these standards.
