Parsers exist in World of Warcraft for 12+ years, and nobody is salty, fear them or feel "insulted" by them.

They help a lot in general balance and rotation practice, because an awful thing, called "StoneSeaSomething" won't help me optimize MCH rotation or search for a better solution/combination/rotation. It doesn't help to improve either.

As for FFXIV, i just feel that people here don't want to improve, play casually and fear parsers in general. However, every good player out there in high/top tier raiding do use parser, so people can't hide "500 DPS 260ilvl" perfomance or afk/liching. Be aware of that, when you join something like "Zurvan EX 260+ ilvl DPS check" farming or something.

Also, unlike healers or tanks, it's impossible to know and give a commend to a DPS player, unless you use parser and see how they perform in general.

p.s. I don't use a parser myself, since i just recently came back from a long hiatus.