No doubt some are. But some are also allergic to tylenol type painkillers. Most aren't.
Also, children with fevers shouldn't be given aspirin.
But carve out those two exceptions, which is perhaps 5% of the market, and if common sense drove consumption habits, 95% of painkillers bought would be aspirin.
Aspirin and the other NSAIDS cause a great deal of gastro-intestinal(GI) ulcers and bleeding, causing anemia and, not infrequently, death. That's why they developed COX-2 inhibitors, aka Vioxx, Celebrex and Bextra.
And unfortunately, some are saying that asprin can reduce the body's ability to clot blood quickly, which can promote retinal/macular problems when a little bleeding can turn into more than a little. (Maybe good for preventing strokes, maybe not so good for eyes.) I suppose this may have ramifications for some pre-menopausal ladies, too.
Platelet aggregation is irreversibly inhibited by aspirin.
Pharmacodynamic interaction of naproxen with low-dose aspirin in healthy subjects. (Check "Related Articles", upper right near the title at PubMed)
CONCLUSIONS: Naproxen interfered with the inhibitory effect of aspirin on platelet COX-1 activity and function. This pharmacodynamic interaction might undermine the sustained inhibition of platelet COX-1 that is necessary for aspirin's cardioprotective effects. That's also why it's prescribed to protect against the most common form of stroke, but not the worst kind, i.e. hemorrhagic stroke, aka bleeding in the brain.