A member of the WH Press Corps is going to get far more scrutiny than someone getting a DOD pass. Not only are you close to the President and administration officials on a regular basis, but you're much more important to the message the WH is trying to get out, and there are only a few people who are eligible to cover the WH in the first place because it presumes some professional background. Someone getting a day pass every day for a couple of years is also an unusual case.
This Gannon incident is obviously bad news, but it's such a stupid little thing that there's nowhere for it to go. Ooh, America cares about the WH press corps. Whatever.
A full investigation takes time. Lots of it. No one is going to do that for a day pass.
Not that unusual. Apparently there are several others in there who also routinely use day passes (including a Naderite).
No, they're not. The daily pass was a routine security check based on name and Social Security number and checked for anything of a threatening nature, not even close to the scrutiny you seem to imagine. The hard pass, which Gannon did not have, does include a more expansive check.
Oh, and I didn't say DOD "pass", I said "clearance" (as in access to classified material). Trust me, that is a very in-depth investigation.