#17 listed a few reasons as to why NA viewership could have been lower. I doubt you actually the know reason yourself so I'll fix your last comment for you:
"still korean viewers were simillar to last years, I think its whats been happening to western scene (what blizzard been or rather havent been doing) that could have caused this".
I'm personally very invested in watching APEX, even getting up at an ungodly hour just to do it. But I can't tell if other western viewers may have lost interest because the last APEX tournament with western teams didn't have one (again), or because of the long production (again) or if they're just looking towards western events or if, as you said, Blizz has pissed them off and getting up was no longer worth it.
For the most part the whole event isn't geared towards western viewers so I don't think comparing those particular numbers is that impactful. Maybe if we saw a dip in overall Korean viewership (I don't have the numbers so I don't know) then I think it would be a bigger cause for concern.
More than anything I want to ask, do you want Overwatch to succeed? What do you think should be done to make that happen? Pointing out flaws in a system is part of constructive criticism, another part is to bring forth ideas an possible solutions. In your original post in this thread you said you didn't want to sound negative, but without suggestions you can only sound negative, instead of constructive/critical.