One of the main reasons is that people saw success of indie titles like Hotline Miami and To the Moon and those games inspired millions of people to start making their own games. I know for a fact that the reason I started game development was because of games like To the Moon and I'd guess you're the same way?

Tools like RPG Maker and Game Maker have actually been out since the 90s, it's only when we start seeing indie developers have success with it that we start doing it ourselves :)