For the last 10 years that I've been watching anime, can someone please explain to me why every season follows the exact same pattern?

- 1x either good show (like this, arslan, etc..) or REALLY good show (Death Note, Code Geass, FMA, Shin Sekai Yori, Fate Zero, etc...)
- 1x pretty good show (gundam, zestiria, etc...)
- 1x barely watchable show that you watch to just keep time passing and avoid procrasterbating (bungou stray dogs, etc...)
- 1x weekly episode of naruto

and the remaining 30x shows that season are absolute shit that I can't imagine who the fk watches it.

Why can't they just have ONE season of like 10 actually good shows?? I can't imagine half the shit I see on Anichart gets even a third of the ratings of the good shows.