I think valuing every human equally is a bit arbitrary.
Everyone should begin with equal valuation to society (the only meaning of 'worth' I think a human can really have), but people's actions and abilities should influence this valuation; the more you can contribute to society, the better treatment by society you should receive. e.g. a scientist should have greater 'rights' than should a [insert mindless job] who should then receive better 'rights' than a criminal.