Why do lots of people take aspirin daily?

Interviewer: There’s a big headline tonight about modern health. Forty-three million people are taking some kind of aspirin every day to prevent heart attacks and strokes, but now the leading medical journal JAMA says there’s evidence that daily aspirin could be linked with a small increase in macular degeneration which can cause blindness. There’re lots of questions...Tonight ABC’s chief medical editor Dr. Richard Besser is here. So what exactly does this study show?
Richard Besser: Well, it is a study out of stray. They looked 2,400 people for 15 years and found that aspirin doubled your risk of macular degeneration which, as you said, causes blindness. The risk is small. It’s only 3. 5% , but if you add that to all we know about aspirin causing internal bleeding, you really need to make sure you’re someone who’s gonna benefit from being on aspirin.
Interviewer: So all the people who’re being given aspirin, who take aspirin, think it’s for their health, where do you start today, what do you ask your doctor when you are going?
Richard Besser: Well, I mean, clearly if you have a heart attack or stroke, it can be life-saving. So you need to be on that drug. Then the next thing, if you’re at high risk, so to find that out. Did someone in your family have a heart attack or a stroke at an early age, or do you have other risk factors like smoking, high cholesterol, high blood pressure, diabetes? If you have those, your doctor can actually tell you what your risk would be if you were having a heart attack. The bottom line is if you’re at low risk, you don’t want to be on the drug that can cause problems.
Interviewer: And you’re telling me even the tiny aspirin, that’s still aspirin.
Richard Besser: That’s right. It can cause problems.
Interviewer: OK, thank you, Richard Besser.