Heartwarming - The use of big aperture

A direct shot, simple which tells the story in the simplest way. It was a reaction shot, I didn't have time to plan for the shooting angle, lighting and the framing, I just fired right the way and it works. Someone say it is not suitable to use big aperture to blur the background in street photography, but I think if it suits the purpose, you can use any aperture. For this image, I don't it will be that impactful if I didn't blur out the background because the background will become the distraction of the mother and son(the subject).