I was wondering the same thing. There apparently were 15 fatalities and 30+ injured. I would think some of those were from gunfire.
There definitely is a vetting process and it's not taken lightly at all. Whether the vetting process is sufficient can certainly be debated, but it's definitely part of the process.
The tiktok stuff is definitely a topic of discussion and debate, and there definitely are issues with corruption and other stuff that shouldn't be happening, but the military is a huge organization. With 1.3 million enlisted, and close to 3 million individuals work within the Department of Defense. Most take their jobs seriously, but there are a lot of knuckleheads among those 3 million people.
Some aspects are, sure, but it's really not any more of a joke than most large organizations.
There's a ton of security on any given military base, and there are extensive rules and regulations governing the behavior of both military and civilian employees not to mention contractors. That said, people are people and your security is only as good as the people responsible for said security.