I don't understand this way of looking at things. I sometimes learn something new by answering a question from someone who is looking at things from a different direction than I am, or discussing something I don't have a quick answer to. That helps both of us. If I don't even have to think about it, it helps the other person be immediately productive (and learn something) at the cost of taking me out of "the flow" as opposed to having them beat their head against it for who knows how long while I get a a couple more minutes of uninterrupted time. I can hop back into "the flow" pretty much immediately.

If it happened every five minutes that's a different story.