I wouldn’t necessarily say horrible, but definitely a bit too abstract for me to really enjoy it
I guess there‘s people who are into that?
I also like the fact that I got a feel for the author’s writing style. Because I’ve seen some other books of his that sounded interesting; but now I know what I’m getting myself into. (To gain this ability of being able to judge the author‘s style for myself and to form this image of them and their works is something I really enjoy about reading.)
And it’s definitely not all books on this list that are this difficult! I just kind of picked two difficult ones in a row? But now I’m reading 妊娠カレンダー by 小川洋子, the author of 博士の愛した数式, and it’s easier than 博士 and maybe a bit easier than コンビニ人間, even.
The 芥川賞 winners tend to be more on the literary side where you might end up with lots of question marks and 複雑な気持ち at the end. Which is a thing I enjoyed for something like コンビニ人間, but if it’s too many question marks, like with this one, then it’s not that enjoyable anymore. 
I’d definitely look into the 直木賞 as well if you’re looking for a bit more „mainstream“ prize-winning books! I think there’s lots of heartwarming, more „laid-back“ accessible stories to find there à la 博士の愛した数式 and コーヒーが冷めないうちに. (Ok, I guess that one didn’t win the 直木賞 but the 本屋大賞
. I think the type of books they award are relatively similar though; 大衆向け, ergo books that a wide audience will enjoy)

So I hope you’ll tell me 

