In a certain respect I will agree with the article by Zoopercat. Presenting default this is what you should be using for X fight does limit player customization. However we do need to follow some sort of guide. Myself, I barely have the opportunity or time to refine a set build, let alone swapping talents around by fights.
As a result, designing fights that require playing a certain way to be successful have driven me away from any more progressed form of play. Jumping around changing specs and builds may make the game more exciting for many, but for me it leaves me at a loss. So my only choice is to gear up to a point where it does not matter how I play, or just not do the content.
Currently I am choosing to just not do the content.
The advantage during Wrath with the cookie cutter build was it allowed you the opportunity to practice and refine your rotation. When we started seeing talent swaps, and needing specific gear sets it became to complex for me. I can’t tell you how many gear check me questions I fielded where people were trying to stack certain stats that were published as best and doing more harm to their DPS.
While gear with random stats may encourage farming sets to get the best. As long as people write guides and determine this stat is better than another and these spells need to be taken for certain fights. There will always be a cookie cutter build of some sort