Absolutely. Most of the shooters I know are buying ammo whenever it is available, regardless of whether they need it currently or not. You can't keep it on the shelves precisely because you have people dedicated to buying it as soon as it appears on the those shelves (actual or virtual).
Twenty one years ago, my next door neighbor invited me to his house because he had something that he wanted to show me. He had dozens of guns all across the floor of one of his bedrooms. Then he opened his huge gun safe and it was completely packed with ammo from top to bottom, there was no room left in it for even a hand gun. It is pretty humid here so I asked him if he had any desiccant in the safe to help keep his ammo from going bad since he had enough to last for years. Of course he had no idea what I was even talking about, and got mad at me for being a know-it-all.
If you are going to hoard massive amounts of ammo make sure and store it correctly. Unless you live in a very dry place... put it in an air tight container and include packs of desiccant otherwise after a few years your powder will be affected and your brass and even primers can become corroded. This results in unreliable ammunition.
In my neighbor's case I should have just left my mouth shut because he has been unstable since the day that I met him. Every time I hear gunfire, I assume that he has just killed his wife and/or his kids. Fortunately we live in a neighborhood where other neighbors down the hill from us sometimes do a lot of shooting behind their houses. My neighbor's wife constantly berates him and he is always taking it out on their kids. It is a screwed up situation. I am glad that he doesn't bother to go to the range ever and has ammo that has been improperly stored for over 20 years.