I used to be an avid watcher of American series, however I felt that they dragged on quite a lot and after the second season I would be forcing myself to watch it all. When I first learned about Asian Dramas I was somewhat skepctical because American stuff is usually hyped to be the best of the best, and if the best of best had let me down, I was sure that Asian Dramas would too. My first one ever was actually a japanese one: "Hana Yori Dango". It was light hearted, fun and completely different from what I was used to. After watching Jdramas i decided to change my mood a bit and started watching Kdramas. I loved it! Asian dramas don't drag, have a mix of various elements (for example in a melodrama there may a high number of funny scenes) and tackle a lot of important issues. I think that kdramas try to cater the consumer, yet they are original and have these concepts that have never been tried before. I don't watch American dramas anymore, now I only watch Kdramas, and Jdramas (these ones very rarely tho).
With lower budgets, comparing with American series, kdramas have great cinematography (Goblin, Chicago Typewriter), great OST (Teacher Kim, I really liked it), and great plots that tackle present issues (Teacher Kim, Descendants of the Sun, It's Okay It's Love).
I mean, it's just my point of view and I respect everyone who feels differently