For me, someone who wanted to build a NES Dragon Warrior or Final Fantasy clone back in the early 90's and had no idea how games were even made, let alone owned a computer, the idea today that I can show my kids they can build a game without them needing to fully understand how to code is mind blowing.
I think that's really why it's so popular: "anyone" with an idea can sit down and cobble something together that looks like a video game. A lot of people will give up when they realize you need to know more than "drag and drop" to customize your game, but it allows a lot of people with game dreams to dive in who would otherwise simply never try because they don't know anything about programming.
Now where did I put those maps to my Fantasy Dragon Quester 2-d jrpg game?