Would you like an in-game parser?

[Reynhart]

Once you know what that optimal rotation is, a parser just tells you how well you're able to execute that rotation in a combat scenario with actual mechanics and things to dodge or moving enemies.

There's more to "how well you're able to execute that optimal rotation in a parser". Once you are level 60, your rotation doesn't change regardless of your gear. For example, if a tank likes to play safe and stack parry (Whatever usefulness it has is another topic entirely), then the parser will show lower numbers compared to other tanks. If that tank managed to beat SSS with that setup and tanks perfectly, then, there is nothing wrong about him. BUT his lower number can harm its progression in a damaged obssessed group.

You know, like back in Novus time, where you were garbage if you didn't speced full Det/Crit even if it cost millions.

Another thing I fear is the dreaded "opener". You see lots of videos showing xxxx DPS opener, with very short duration parse. If, for some reason, your opener is not optimal, people can judge you within a minute of the duty, even before anyone will have the opportunity to deal with any mechanics. And yes, I've seen such "Oh, you're doing xxxx DPS on your opener it's good/bad..."