Despite being a "no" everyone everywhere has a parser and can look at their active read-out to know exactly how much damage they are doing and when. As a ps4 player, i can only ask others how i did. At the end. Knowing how subtle changes can affect my parse is vital to mastering a class. Like say on BLM, knowing when to throw thunder3 instead of foul while in ice because you want more DoT uptime since it fell off, but if it hasn't, it's not worth using before anything else and is a dps loss to use again unless it's falling off. Unless you're observant and taking note of how everything lines up in your head(even then, really), you could easily improve your imperfect rotation until it's about flawless.

GRANTED, some people might harass others about low numbers. I think we should all have our individual parser going and consent to sharing it with others. It's already against ToS to shame somebody for low numbers, sooo