Yeah, you're right, I'm getting soft!
The consequences could have been nasty, and yes that should be considered. However, the point of prison is that it is supposed to be for those who are a danger to society, and who need to be locked away to keep the public safe. I'm not sure this guy fits into that category, it seems to be more a moment of madness.
Of course if he had some indigenous blood in him, he would get a "restorative justice" hearing, a quick one-on-one with his "victims" (I guess the Skytower management and the aircraft owners), a slap on the wrist and released into the care of his parents...
Hmmm, now I'm getting cynical!