I agree entirely. What Facebook provides is certainly not the only way to accomplish (or access) messaging/photo sharing/whatever. However, despite the limitations of such Facebook services, a large percentage of the population still choose them over other available options with more functionality. Perhaps the extra functionality isn't really that important to the average internet user. Or perhaps the average internet user even prefers the lack of extraneous, seldom used functionality that confuses and distracts them from their core purpose in using such services.