Blizzard seems to want two things to be the case. For choices to matter, and for there to not be cookie cutter builds, where everybody just ends up with the same talents choices. Those things seem to be linked together. After all, if there is a cookie cutter build, and you are basically forced to pick certain talents, then you can't really choose whichever talent you personally want.
But I still feel like Blizzard doesn't quite realize that the covenant system will probably do the opposite of what they want to achieve. I usually just pick whatever talents I feel are the most fun to me and don't care too much about guides. But one of the reasons I can afford to do that is because I can switch talents so easily. If my choices are "wrong", I can easily fix that.
However with the covenant system I will now more so than ever pay real attention to what's best, because I don't want to be stuck with the wrong choice. They want our decisions to matter. But if our decisions matter, that means you can't afford to pick the suboptimal choice. It matters too much.