"Hey, I cannot beleive it.... this guy just sent me an email asking what renderer I prefer. Who does this guy think he is....I refuse to respond.... ha ha.... that will show him."
And you are back to assumptions and projections on others, approaching this whole issue in oversimplified manner and very black&white way. Everyone tried to explain that's not what most people think at all. Usually these emails are not single questions like this either, they're full blown essays with many often quite open ended question. Replying to them takes great energy and lot's of time, which is extremely scarce commodity for most people, esp. professionals who are over-head with deadlines, and those few minutes they want to take off, they prefer to do so in forum, or just forfeit completely and spend with family/friends/hobbies.
If someone doesn't reply to you immidietely, to full extent, or not at all, it doesn't really say much about it, except that he probably has valid reasons to do so.
You continue to look at things from a limited personal perspective, instead of trying to understand others. You can't just call yourself emphatic and yet keep narrow outlook on issue.
And I already explained that blogs have nothing to do with your understanding. What about media ? Do you think that just because journalists write articles, they expect to receive 10 000 emails from readers to continue discussion, to all of them obliged to answer ?
Sometimes there is a place for discussion, sometimes there isn't. But the playing field is not automatically private domain and no one is obliged to partake in anything.
You can't just automatically assume that just because someone started any digital venue or outlet (either through blog or forum participation), he is now obliged to share more with you (of his time/knowledge or other commodity). That is completely false equation and I am surprised how would you arrive to this logic ?
You continue to hold on assumption that people owe you part of their privacy and personal time based on common courtesy and easy reachability, which is often thought fallacy of current digital age.
When I begun CGI, it was in my mentality that I wanted to share. It's nothing really altruistic, it's more about my choleric personality, traits of which are just often extrovertial. Since the last 3 years, I almost always answered every question into my workflow and everything and answered hundreds of threads asking help on CGArchitect. But that doesn't mean it's limitless and fills my whole day. There is cap to how fast and to what extent I am even capable of answering everything. Hell, I don't even answer all work offers, I don't have time. I prefer to help other cg artists then to even say "sorry I don't have time for your project". That's how invasive things can be, and how little time most people have.
Last thing: Imagine you wanted to get home to your family. But every stranger on street demanded your attention for 20 minutes otherwise they would consider you rude and ignorant. How would you find it ? When would you get even home ? Internet is the same thing, we're not closer to each other just because it's easier to reach people.