Realistic arguments? The arguments against parsers are either self-contradictory, explicitly ignore inconvenient facts that nullify their concerns, are based on feelycraft "I'd be judged by other people" paranoia, or outright hallucinations of an imaginary person who is explicitly reportable under the rules anyway.

The only argument that has any weight is that numbers by themselves don't help you determine what exactly is going on. And even that argument is considerably weakened by the solution to that concern: those concerns are alleviated by, oh, I don't know, comparing them to other peoples' performance in a place that I'll call...FFRecords. Or uptime/performance analysis tools. You know, those horrible evil things the anti-parsers think are even worse than the idea of adding a parser, because heaven forbid you COMPARE yourself to something. Ewww.

I have yet to see a single argument against parsers that isn't a flimsy veil for "I don't want to improve or allow other people to see that I have room to improve".