For example, I recently watched a video about streamer heads- something that is actually quite simple to understand and describe. However, the explanation given was convuluted and full of what seemed like deliberate use of technical sounding (but inaccurate) jargon. This really turned me off, and I made me think that either the "teacher" didn't really understand what he was teaching or was trying to prevent actual learning, small wonder that beginners are often intimidated when confronted with this style of instruction. Compare this to excellent streamer videos from people like Kelly Galloup or Nicklaus Bauer that are simple, matter of fact and easy to follow and you'll see a clear difference.
There's nothing in flytying that can't be explained simply, clearly and accessibly. So I'd encourage you to steer clear of anything that isn't.