Cause I seriously think photography will not have it's value today without them. In still life, commercial photography, even landscape and wedding portraits for example, shots can be possibly duplicated, depending on the control we have over our environment, subjects, lighting and tools. In real life wedding portraits, subjects change but countless bridal studios have duplicated the same pose, the same background, the same props, etc. and etc... Even in wedding event photography, photographers have duplicated similar poses with different couples, though not exactly the same, but similar. In landscape photography, if the light isn't right today, we can try again tomorrow, and tomorrow, and tomorrow... till we succeed, but the mountain doesn't move. And in studio still life photography, we have all the control we need to duplicate that cabbage shot over and over again.
The real challenge comes in street photography and photojournalism. No subjects are paid to do what you want them to do. And God doesn't always give you the best light in that moment you saw someone jumping over a puddle of water, for example...(if you are even thinking of duplicating that Cartier Bresson's shot).
It just doesn't happen. Each moment is unique. Each shot is priceless. Each subject changes. Each human ages and dies. Each detail wears out through time. The lamp post rusts. The structure gets demolished. The machines grow old. The homeless disappears. The children grow up. People migrates.
Street photographers and photojournalists being the least paid or non-paid photographers record the MOST Precious moments in life. Photojournalists risk their lives. Many street photographers go unnoticed, unpaid, unrecognized and even unappreciated.
Unlike commercial photography, the motivation is often money.
In street photography, it's ALL about passion. The passion to keep memories. The sickness of NOT being able to let go. We want to record every moment we saw and tell it to the whole world!