The issue, I think, is with false positives. If I were a recruiter, I'd pay attention to how someone would like to represent themselves, and that would include not altering the data they gave, so, I'd basically copy-paste the info from the First name field, and act like it's natural to call you that.

Of course if you still find satisfying work with good pay, then your system works well. But I'd like better accuracy in, say, an email spam solution.