1) It's mostly about subjective impressions and often weird ideas of what a suitable date/candidate must be. There are no official rule books or guidelines about how to proceed. It's not about hard skills and efficiency, it very much revolves around soft skills, presentation abilities and invisible chemistry.
2) More often than not both parties in dating/hiring aren't serious about conducting a transaction and getting to a serious business. It's about meeting new people, hanging out, checking the pulse of the job market but no more. Misrepresenting oneself, one's abilities/features and intentions is the norm with both dates/candidates(companies), which leads to a lot of frustration and bad feelings, keeping the success rate of activities in the both fields rather low.
Different industries, similar problems. And for the both of them no technological/software solution in sight.
P.S. See how "candi-date" is linguistically just a particular case or subset of "date". Just another validation of the point.