They justify that the old system encouraged people to just skill 2 abilities in order to become more powerful. This is a lie because in D2 a lot of skill builds were composed around using 8-9 abilities. They are simply removing one of the best parts of diablo 2 which is customizing your class to different play styles... now everyone is gonna be a copy of each other. If they felt people were just gonna end up resetting their skill trees until they got it right why not make it impossible to reset like in diablo 2 and make people commit to their choices?