Akatsuki no Yona did give it a run for its money though (that came in 2nd, barely edging out OPM). Also, on the bigger anime sites, Shirobako didn't even rank top 5 (it's more popular amongst blog based websites). One Punch Man was the clear winner in terms of mainstream appeal in 2015.
Btw the comments posted on your mal profile are so hilarious. Typical MALtard quality. I loved the comments that tell you ned to watch more anime and that naruto and death note need to be in your top 10/20.
But wtf how did MAL even let you approve that article . Thank god comments are disabled because I can already imagine the pitchforks. Ill have more to say but for now I dont disagree. In fact I had to "adjust" and somewhat change my tastes and be less critical over the years so that i still enjoy the medium. You've seen it yourself where ive been "moe fagging" more than i should be.