As for the points you say, I'm not into real estate, I think often it comes down to limitations from reality. You know, actual _people_ live in those apartments you're trying to have pictures of. Maybe they'll just deny you entry (it's their place, after all, they might be renting and thus not give a damn about you willing to sell the property), in which case all you have to show is pictures from the outside. Or they might only agree to send you pictures themselves, in which case blurry pictures is all you get.
Of course, in general it's mostly incompetence, but hey, if everybody were perfect at their job the world would look totally different, in more important sectors than real estate...