Why limit mastery pages?

I realize there's not a ton of variation, especially between the pages for similar champions, but I can think of no valid reason why we're capped at 20 mastery pages. With rune pages, we can buy more... but with mastery pages we can never surpass 20. For most, 20's sufficient. I, however, like to be prepared for all eventualities. It's why I created item sets for every champion I might find myself playing, and for every role they can play. If it weren't a crazy IP sink, I'd probably have rune pages in the double digits to give myself flexibility (since you can't edit runes in champ select). You can edit your masteries in champ select, but I'm no good at doing that sort of stuff on the fly. Why can't mastery pages just be unlimited like item sets?

While we're at it, why not be able to pick and choose which champions you want those mastery pages (and perhaps rune pages as well) to show up for, like with item sets. That way you don't run the risk of entering a match with the wrong masteries/runes, and you can find the ones you want without difficulty. People are often asking for the ability to organize their mastery/rune pages without having to delete and remake them. This could do the organization for us, as item sets automatically alphabetize. Why can't the same be done for masteries and runes?

Anyway, just some thoughts I had.