If a rifle has excessive headspace it's not necessarily a bad thing.....It's not good either.....it's just that it shouldn't have excessive headspace and the smith is absolutely correct to send them back.

It reduces case life dramatically and can be potentially dangerous if it's extremely excessive in that it can cause a case to rupture in firing and potentially injure the shooter. Companies like Remington should never let a gun out with excessive headspace...it's so easy to check.....