GMS arguably provides the fastest playable 2D prototypes of a game when compared to any other engine. This in itself is a huge advantage as you can try out wacky ideas and see how it plays out in practice.
Another big advantage is its accessibility. GML is designed to be very newbie friendly and it even goes as far as to be forgiving of a lot of coding's "bad habits".
Very true. You can get used to some things that are terrible coding practices and later on have issues with that. However, being able to move forward with your project and not linger on a small (and ultimately unimportant) mistake is paramount, especially if you're new and just want to make something. As long as you get the end result you wanted, none of that "clean code" matters.
