Irritation for the sake of agitation

I spent this past Saturday working at an event held outdoors at downtown Tampa's Curtis Hixon Park. It was a food festival and I was at a tent near the front of the park selling admission wristbands. There are fountains there that parents let their kids play in. From what I could tell, it's something that some people do every weekend as a lot of the people seemed to know each other. The parents set up lawn chairs on one end and watched their kids go nuts, running back and forth through the water.
About an hour into the event, a middle-aged woman toting a cart full of stuff pulled up and began assembling a display (I don't know why, but I didn't take a picture of her. Sorry about that.) that featured pictures of aborted fetuses. Oh good. An anti-abortion protester. With a microphone. Swell. Now I get to spend my Saturday morning listening to this. But I get it. It's a park. Public space and she has the right to free speech. Fine. Whatever.
But here's the part that makes me do this...

The area where she set up her display was right in among the parents who were there to watch their non-aborted fetuses play in the fountains. Not only that, she got into verbal arguments with at least four different people, including one clearly pregnant woman. Isn't that kind of like getting into arguments with people in line at Dunkin' Donuts while you're handing out flyers for Dunkin' Donuts? Again, she has the constitutional right to free speech, but I question the logic behind an anti-abortion protester targeting an audience that would not seem to be in the market for an abortion. They were far enough away from me that I couldn't hear what was said but the fact that they were arguing indicates to me that the parents were irritated by her mere presence. I'm betting that they were probably less than thrilled with her graphic displays in full view of their children. If I were protesting that "Meat Is Murder", I wouldn't set up outside of a vegetarian restaurant with pictures of mutilated cows, unless I wanted to annoy and agitate the people who might be predisposed to take my side. What's the damn point of that?
Yet another item on the seemingly endless list of things that I simply do not understand.