What parses can tell you: A very general overview of how well a person knows how play their job, their grip of the opener/s, their average DPS across several fights to see for consistency.

What a parse can't tell you: A persons temperament under stress, how quickly or slowly they learn a new mechanic or adapt to change, how well they can communicate an idea, how they fit in with the group as a whole.

It's perfectly fair for a static to want parses upfront, they can't tell you everything about the player, but it can at least tell you quickly and effectively if they have the technical skill to meet the groups goals. But it's definitely not the only thing that matters in a static. Even if you have incredible parses if you don't fit in with the group, you probably won't be staying very long.

More often than not if things become toxic over DPS it's because there was a miscommunication of expectations. Not because a tool is displaying the reality of numbers.