clarification of ignorance

I had a post on the book launch’s facebook event page yesterday that the book was too expensive for so little pages.
This person, who does not know me, who knows nothing about my story was able to post this. Therefore I felt that I had the right to post a response brusquely detailing why I had come to that price, thus relieving them of their ignorance. They are not coming to the event. I feel that’s probably the best choice that they could have made. They also deleted their comment, taking with it my comment where I gave my reasoning.
The post pointed out the following (for those who might want to see it):
The price of the book was set in accordance with mainstream market prices for new books. It was also set in consultation with another self-published author, who actually told me that I was setting my price a little on the cheaper side.
I also pointed out that there was no obligation for people at the launch to buy a book (though it would be appreciated). I know better than anyone that has gone to book launches and art show openings that just being there, observing and listening and asking questions is support enough for some people.
What I did not explain, though perhaps I should, was that on future non-launch orders that are placed with me, I will not be charging postage on my orders (initially anyway). I can absorb that cost with having the books made, and shipping without cutting off any potential profits that I might make.
All this left me with a sour taste in my mouth. It reminded me of all those people who said that writing isn’t really work.
To all those people I issue this challenge:
45 000 words in a week. Your first draft is your only draft.
It cannot be about vampires vs werewolves, fallen angels, post-apocalyptic teens or anything else that is in the market at the moment.
Also it must be perfect. NO spelling, grammatical or continuity errors. Your characters should be well rounded. I must be able to feel like I am walking in your settings. I want to feel everything that your characters do.
Suddenly, not only does this become work, it becomes an impossible task.
I know that.
Which is why I point out that writing is neither easy, nor is it a weaker option for a career path. You must be able to pick the flaws out of your story. That takes time. You need to be objective enough to see where plot holes have been cut into the road of your story. Again, this takes time.
Perhaps ignorance is really the only option for those people who turn their noses up on creative career paths.