I agree, a lack of response is not only annoying, but unprofessional. Location is obviously something to include in an ad, since shipping is so problematic here. Pics aren't easy for everyone to do, and not always necessary. When I post an ad for baby corn snakes, I'm not posting pics of them all. I'm not taking pics and emailing them to people either, unless someone asks really nicely and I'm not that busy at the time. Sure, I intend to sell them, and I will sell them all eventually, but I've got other things to do:-)
What I find annoying is when I say "reply by email" and then people PM me. I hate getting an email that tells me I have a PM, and then I have to go and read that. Just use email!!