As mentioned above, some cars happen to come from the factory with a poor alignment. Or a decent alignment, but at the limits of their specs. Alignment specs for particular cars can sometimes be difficult to find, btw.
I may have missed which car OP is dealing with, but many can come with a significant amount of negative rear camber from the factory - for enhanced ride comfort as I understand it. This happens to be what I'm dealing with. Frequent tire rotations masked the problem until all 4 tires now have significant inner tire wear at 30K miles.
When looking at the tires/wheels visually from the rear, the amount of negative camber appears to be at the extreme tolerance of factory specs, if not more (out of specs).
I just visited an independent local shop that suggested that they bring the specs on rear camber as far positive as possible, while still staying within factory specs.