I'm sure you wouldn't want to be the person stuck with completing 90% of the work for a group project at school while the other team members got to slack off but still receive the same credit. And if there were a way to prevent that from happening, you'd probably want to make use of it for any upcoming group assignments. Parsers are an objective way to measure player contribution in dungeons/raids, so that one can monitor other people's input but also strive for personal improvement.

TLDR: In a single player game, do whatever you want. But by engaging in an MMO, you can't just think of yourself and whatever is most convenient to you. Parsers provide a means of gauging everyone's effort in a TEAM BASED scenario. There is no reason to prohibit parsers for day-to-day use; only those abusing parsers should be reprimanded.

Also, it's unfortunate that the term casual is now associated with being bad and elitist with being a prick.