You're not getting it. The mounting process needs to come close to aligning the scope with the bore WITH the reticle/erector tube centered. Much of the time, installing a scope in out-of-the-box mounts won't result in the scope being aligned, for several reasons, including an uneven top on the rifle action (not uncommon on factory rifles), bases that aren't machined precisely, and rings that also aren't aligned with the rings.
Add up all those factors and scopes will OFTEN be misaligned with the bore, even though there's still enough adjustment range in the scope to getting sighted in. Most people don't understand this, which is why many scopes don't adjust like desired. They may not anyway, but being mounted somewhat crooked doesn't help.
