I'd like to think that I'm part of making this new media better and more satisfying. The best practictioners are often the worst teachers. Such people have integrated their practice so smoothly that they do it without thinking or conscious articulation using some well worn neural pathway. I make use of Sufi and NLP teaching techniques, to gear the materials to be learned to the student rather than simply instruct them. This kind of jealousy, while understandable and practical from a Machiavellian perspective, does not serve the field as a whole, leading to fewer people who might be prepared or able to return the favour in the long-run.
Teaching is also a great way to get known.
If a small percentage of my students get jobs in my field, then I get to be well known in the industry. As a freelancer working in the 'invisible' field of multimedia programming, this is invaluable and I have got several good jobs through this route. I can be hired to give lectures or instruction by institutions or companies who wish to build on interactive multimedia competences. If you want to make slideshows, ask someone else. My angle is more thorough-going and should outlast the next version of your current multimedia authoring tool.