A bad advocate undoes the work of a good advocate. Bill Nye doesn't really use scientific methods. His last show was a mess, because he made assertions he didn't back up.
Bill Nye has done good work on the past, but he is undoing the work he has done lately.
Perfect is the enemy of good enough. We have congressional reps who proclaim there is no global warming because it still snows (while holding up a snowball on the floor of Congress). Again, every advocate is needed, even if they make mistakes (as we all do).
the world needs more Beakman
If you get children pumped up about science and the natural world, does it matter if you don't use scientific methods?