My Problem with Runes Reforged.
Instead of many mostly incremental choices about stats, new runes concentrate the power down to a more focused set of choices.
I'm worried you're limiting the amount of choices that we can make, thereby increasing the amount of cookie cutter builds. This happened with the previous mastery changes. The previous system had better diversity owing to it's more masteries (There were 20,19,18 masteries in the respective offensive, defensive, and utility pages). Furthermore, the system allowed the ability to put all of you points into one page, thereby allowing one to solidify a role, or, change one's role completely. That being said, keystones were an interesting addition, as they certainly are meaningful, but, because they are so meaningful, they leave little room for other builds. If a mastery point is so meaningful (overpowered) that you must take it to win the game, it's not really a choice then is it? Being able to make small incremental choices allowed there to be many more types of builds and play styles, as it lets you build the champion the way you want to play. Allowing this freedom of choice greatly increases the types of strategies and counter strategies in the game.
Imagine there was a world where there was only 9 meaningful things people could do in life and they could only choose one of those 9. If one lived in this world, one could observe 9 types of people. Now imagine a world where small incremental choices culminated into a meaningful and diverse one. Living in this world one could obverse a more diverse set of people. This hypothetical exercise illustrates the differences between the previous mastery system, the current one, and the one to come.
In conclusion, concentration of power, will only serve to promote a few playstyles. Building the system to allow different builds not only makes the game more fun, it allows for greater strategy.
If anyone would like an explanation of why diversity is good for league please let me know.