If you shoot at someone and miss you still go to jail you dumbass.

Even Florida, which has some of the strictest laws regarding gun crimes in the USA, allows probation for assault with a firearm under some circumstances.

The courts have many punishments available to them aside from prison. Attempted murder is usually considered a very serious crime in and of itself deserving a prison sentence, but this wasn't attempted murder.

Aside from prison, courts can and do sentence people to suspended sentences, community correction orders, home detention, fines or other sentences depending on the circumstances and severity of the crime, the likelihood of rehabilitation, the previous character of the convicted person, any previous criminal record, the presence of aggravating or mitigating factors, whether the accused exhibits remorse, etc. Some jurisdictions (e.g. Singapore) allow corporal punishment as an alternative to prison.

In this case the person is a veteran who has served his country and the court believes that if he gets treatment for his PTSD and drug abuse he is not likely to re-offend. Who the fuck are you, who knows nothing about the case or the person, to say they're wrong?

Prison is not always the best or only option. That's the whole point -- especially in the USA, where your prisons are completely fucked up and people come out of them worse than when then go in. If you want to fuck somebody up so that they become an even worse criminal, and screw what that does to society, you send them to prison.