I was reading this story last week, and it reminded me of a conversation I had with my mother right after I took a job teaching jewelry design at a local craft store. She thought I was crazy for teaching my techniques to people who could become my competition. I failed to see the harm. Yes, I could share th techniques I have learned and developed, but no one else is going to design the same way I do.
The joy of being an individual is knowing that someone who has the exact same skills you do will never be exactly like you. You will always have different values, different motivations, different goals, different tastes.
In the end, you really can’t do any harm by encouraging competition by teaching those around you! (Plus, we’re all lying if we say we aren’t inspired by someone else’s work.)