There's nothing stopping the civilians from reporting it publicly AFAIK. There's enough cameras in the sky that we'd have footage of a few. Especially from all the commercial fights with passengers.
Part of the issue is the stigma. Commercial pilots are afraid to come forward, and that’s why Ryan Graves came to this meeting because his mission is to reduce the stigma so pilots feel safe reporting this issue.
I'd agree on some pilots, and sure they should post more unexplained things for analysis. But given how many people are eagerly into bigfoot or cryptids, it's not like every pilot with some kind of evidence would feel unsafe sharing it.
Pilots, both commercial and military, are constantly under scrutiny to maintain a healthy mental state for fear of their license being revoked. You can not be mentally unstable and be a pilot. For years it was generally well accepted that people who believed in UFOs are crazy, so pilots have kept this to themselves for fear of retribution. Go ask any pilot how they would feel reporting something moving in unexplainable ways right up against their aircraft.
That's why I said evidence. I'm not expecting them to tell tales of UFO sightings. Having a video of something does not reflect on your mental state (unless you faked it). This issue also doesn't apply to passengers and there's lots of people in the sky who don't have a pilot's licence to protect.
Most planes aren’t equipped with any camera systems. The videos commercial pilots and passengers use are their phones which have trouble focusing on objects half a mile away (which is very close for an aircraft to be next to another one but very far for your phone to focus on).
Military pilots do have camera systems like the ATFLIR pods on F-18s but the pentagon only declassifies those videos when it’s useful - like when the Chinese jet made an American military plan fly through its fumes recently
Blurry photos do not stop people from posting them in many other cases. Planes do not have to be equipped as such: there's so many people flying with GoPro-s and similar recording all the time that we'd get something popping up all the time.
And that's even if we ignore the claim that people repeatedly see something. If I was a pilot and spotted something weird more than once, I'd make sure I record every flight from then on - can't imagine not doing it.