ELI5 the reason why Papercraft wasn't made for popular champions than Anivia/Nunu though.
I might just be stupid, but I read this comment and thought it dodged Killroy32's question.
I thought what Killroy was after was something along the lines of "If papercraft was made for more popular champions it would've sold better so Riot should look to try this on more popular champions and see how it does."
I was trying to say that we control for a lot of factors including the popularity of the champion when we measure performance. Unfortunately, Papercraft didn't meet those standards even when accounting for for popularity. Alternatively, its likely Papercraft would've performed poorly regardless of the champion we put it on vs. the champion popularity.
If the question was "Why don't we test new skinlines on popular champs to begin with?" I would say it mostly has to do with risk. If we create a theme no one wants and the skin does very poorly - that's not only a huge hit to our revenue but also means far more players didn't get something they would've wanted instead. To me that's kindof a lose-lose for everyone involved.