They are, it seems, taking certain abilities and achievement related enhancements that, in previous games, came as a natural and automatic part of progression in certain skills/abilities, and repackaging them into perks of limited availability.
But the notion that such reductions in options "allow" for greater diversity is a lie. They actually allow for less potential diversity, by forcing diversity in a smaller number of certain builds. Players were nevere NOT allowed to be extremely diverse, they were never not allowed to make pure characters, very limited in certain areas and very gifted in others (and many if not most players had main characters who were exactly as I have just described). However, players did have the option of creating characters who were some what uber. It was an option that some players certainly chose. The Devs seem to be trying to take away such options, and dressing it up as somehow being an increase in options, when in fact it is just the opposite. I could easily be wrong, but I have a strong hypothesis, and there are good indicators to support it that the benefits of Acrobatics, Atheletics and the like will still be in the game. . but quarantined under "Perks". You can be really fast, but you won't be able to gain that extra damage in one handed weapons. You can jump high, but you have to give up that perk point that you wanted to use for enhancing your destruction spells, etc. etc. [/b]
They're trying limit the freedom players have because they know players are smart. Smart players aren't going to waste points in builds that aren't the very best just for the sake of diversity. Noobs aren't going to end up with weak characters. The new system seems to guide the players in order to showcase all perks in ways that make them viable. It's seems easier to make perks more viable when developers can anticipate what a player has chosen before that particular perk the player is looking at.
More options that are viable => More practical choices => More choices.
Hard choices instead of clear cut builds.