This! I was in college in '08 and on a "college budget", but I still bought a case or more of .40S&W and still have some of that left. Watching ammo prices constantly headed in an upward trajectory, I always keep some supply of every caliber I shoot with an emphasis on those calibers that I carry for defense. Now, my inventory of ammo has grown with my paycheck and will continue to do so...at least with the amount the gov't lets me keep.
Also, while it may not necessarily be an "investment" you can't deny a little quote from the owner of Ammunition Depot. "Gold and silver are mighty shiney, but only lead will save your hiney."
Last, it's up to the individual to secure the means to sustain their hobby if they want to keep it. You can complain all you want, but you just have to simply learn that history repeats itself especially with regard to periods of "panic buying" or what some call "firearmageddon".
