Spock had a soul and that is canon. His soul (or whatever it was that made Spock more than the sum of his sexy, sexy green parts) was so important to his friends they quit their jobs, stole their own ship, crashed her, stole another one then got Spock's soul out of valet parking just in time by THISMUCHSECONDS before it (or he) got lost forever.
TLDR: souls are a thing for Vulcans, why not everybody else? Vulcans haven't advanced beyond the concept at all.