I don't know about outside of the U.S., but here "Mythbusters" is a huge success with us science geeks and a lot of other folks, too. The popularity can be explained by this exchange between the hosts Adam Savage and Jamie Hyneman​:

Savage: "Jamie, when we're all done making 'Mythbusters', how would you like us to be remembered?"Hyneman: "How about for our promotion of critical thought."Savage: "And how do you think we will be remembered?"Hyneman: "For blowing crap up."Savage: "Yep"

For all that everyone likes seeing them "blow crap up", there is a lot of science (and writing it down) involved. Personally, I really like that part, too. Not only do I learn cool things, but it some odd way it feels like it justifies the explosions because, you know, science!

What about in real life, outside of "Mythbusters" or a science lab? I've had this experience of debugging something where the final solution is something that I really thought I had tried previously. Since I obviously had not done so, writing down more things would have been very helpful in my process.

Probably a lot of things that we do, cooking, working on a car, woodworking, gardening, etc., could benefit from keeping track of what works and how well. I can highly recommend it.