So here's the thing with the idea that GB Studio and RPG Maker are used to churn out slop... it's not exactly wrong. Now that may confuse you as I said just a moment ago that these engines should not be thrown in the trash just because some... hacks use them to make bad games. This idea is not exactly wrong in that there is a kernel of truth in it, the problem with that kernel of truth is that it is encased in a layer of bullshit.
Said kernel of truth is that when you make game development tools that are in theory beginner friendly those same tools will be used by said beginners to make baby's first RPG or baby's first platformer. This however is not a problem with the tools and in fact is not a problem at all. It only becomes a problem when a consumer base has little to no knowledge about the engine in question and then makes broad assumptions about the engine based on what its users make and not based on what the engine is capable of.