It's not a case of poor spelling, is a case of acronyms and capitalization. "Pearl" would be just plain wrong, and could even imply a completely different language.
When faced with a stack of resumes, it's reasonable to weed out the candidates based on some criteria, even if the approach takes on a Perl vs PERL evaluation. Employers are entitled to use what ever methods they feel meets their needs. If an application doesn't meet the criteria, move on or issue the standard "thanks but no thanks" form letter. Just don't waste the company or the applicants time with condescending "spell it right" crap.