Well, Tiffany, have you considered that this may actually work in your favor?
Your point is, basically, sellers aren't going to get proper market exposure, so they're going to wind up selling for less money. Which is great for you - you should probably seek out those very properties with only one picture (provided, of course, that you like that one picture!) - because you'll probably get a better deal on that house than one that is marketed properly!
All the best,