Because if you can't add your favorite dramas, it's no longer "Best Dramas of 2020" but "Best dramas in this selection". And even in the present case (with add) it does'nt equal, because the first dramas proposed are advantaged (and 2020 is not ended)
I still enjoyed the drama, especially for some Ko Moon Young's scenes. But for me the head nurse thing has wasted the drama, so 9.2 is overrated I have never rated a drama more than 8 (for 212 dramas) and only 8 movies (for 371)
Nana and Jung Da Bin (not in the list :( ) also Seo Hyun is really good in private lives (and Shibasaki Ko too, in 35sai no Shoujo) For the 1st place, no surprise this year, it will be Seo Ye Ji
It does not take very much for change my mind, i read "Please don't hate him" and I wanted to watch. But it's "Please, don't date him" , I don't want anymore ^^
Edit: but this drama was not from 2019? (sorry ^^)
(and Shibasaki Ko too, in 35sai no Shoujo)
For the 1st place, no surprise this year, it will be Seo Ye Ji