I think people can do whatever they want. If they choose to stick all of their recipies on a sight where millions of people could access them, then let them. I know some people don't like to give out any of their recipes. Also anything could happen and all your information could be lost! Even if someone would decide to do the online thing hopefully they would keep a back up.
Another thing.. i believe this idea would waste paper and be a big pain in the you know what! Because i know at my house that my computer isn't near the kitchen. So therefore my mom would have to walk out into the front room, look up her recipe and PRINT it out so she could have it by her side while cooking! Because who is honestly going to waste time running back and forth fromt he kitchen to the computer monitor!? Not me!
Then since she stored everything online, so she wouldn't have to keep a little collection of reciipes, she would throw away the printed version. Which would be more exspensive in the long run to keep your recipes online. You are going to use more ink and waste more paper. Nothing's wrong with a little box full of index cards! As long as you keep it organized in some sort of order it's just fine and dandy. And actually would be less of a hassle in my opinion.