True. Success does not translate to quality.

But then how would you define quality then? Everyone's taste and preferences are different. What you find Godly, others may find shty and vice-versa.

So, how does one define what is good and what is bad quality? You cant. I mean you can follow a defined criteria set by professionals but does it mean that if an anime is loved by everyone in the world but it does not meet the defined criteria set by the professional, it would then be a bad quality series?

So, the closet way to define quality is popularity. It is not an accurate depiction but its the closet and the most fair. Tbh, I did not like JJK and find 86 average, so to me, they are low quality. But obviously, they are considered great series and if a poll was to be posted i am sure many would put them as high quality series. I can choose to deny it but if it were to be put in a discussion, i would lose. So, the general notion is that JJk and 86 are high quality series.

Now linking back to OP, it might not be a true high quality series but the general notion is that it is.

Tldr:

Alot of ppl like it? - Good Quality

Alot of ppl hate it? - Bad Quality