What are your opinions on games made with GameMaker:Studio?

I’m an amateur programmer, and I’ve been using Game Maker for almost 8 years now. As I’ve been using it, I’ve noticed a LOT of people saying it "isn’t a real language" and people should "use a language that takes actual knowledge." However, I’ve seen a lot of critically acclaimed Indie games that have been made with GM:S, including Hyper Light Drifter, Hotline Miami, and Undertale. My question to you is simple: What’s your opinion on the subject?

NOTE: I have NO IDEA if this is the right forum, as I don’t really use FFShrine much.