This is still going.

As long as hard enrages exist based on killing something before a time limit expires, you need the ability to objectively look at the numbers you're putting out. This isn't up for debate. The potency system is certainly a decent way to 'eyeball' something via potency/gcd, but you can have no way of knowing for certain that ABC > BCA > CAB without the data.

All that parsing / meters do is take that data and put it in an easy to read format of Damage Dealt / Time in Combat.

You want it as a personal parser? Fine, go for it.
You want it as a public opt-in parser? Fine, go for it.
You want it a training dummy that'll give you a report after you leave combat with it? Fine, go for it.

But it needs to exist within the game because console players cannot access third party Parsers without someone else's aid. When the tool is that vital, not having it openly available to the player within the game itself is inexcusable.