
while you do have some point. let's be real, majority of readers hate it because it looks realistic or at least that's where the artist is leaning into with the facial style.
they hate it because the art style is not appealing like the generic overly handsome characters we see from all manhwas nowadays which were born from unrealistic beauty standards of Korea.

I mean, not overly thick and sharp eyebrows, realistic eye shape and size (or small compare to the Manga/Manhwa Art Standards)
and the way they always include 'ala' of the nose is possible indication of how this artist is used to drawing real life portraits.
While it may not look Realistic at all, just compare the overall facial features with the generic Manhwa styles and you'll see how I said this one is leaning onto realism.
Realism may not goal the artists want but in the end it made his Art Unique.

Well, once again, I don't find it realistic. Especially considering the proportion errors in the first chapters. The proportions may be trying to be realistic, but the style is absolutely not. The characters have a very basic character design that we find in many other webtoons. Maybe that's the problem. Other webtoons do exactly the same thing but with a more personal and memorable graphic style, while Gap is flat.
Not sure why people are complaining about the art but odo looks like what you see as a good looking Korean guy. Proportions are great just like IRL