Actually, I am not. If I said everyone should load up on aspirin every day, without taking into consideration the possible side effects, then you would be correct, and I would be making a blanket statement.
I included those who should avoid aspirin, unless directed to do so by their doctor. I mentioned the allergic response, I mentioned the dangers if taking it if you have a pre-existing clotting disorder or are on anticoagulants, I mentioned the danger associated with aspirin if you have recurring stomach ulcers.
There is a plethora of information regarding the safety and effectiveness of regular aspirin use, and the various doses from 81mg to 325mg, as well as the associated risks as well, on pubmed.
My point is that aspirin is an effective chemoprophylaxis against many forms of cancer, not just colon and gastro-intestinal, so long as the person taking it is not allergic to it, has a pre-existing clotting disorder, is on anti-coagulants, or suffers from stomach ulcers.