>>85027108>MacguffinsI'm booty bothered people apply that term to them.
It is certainly how most see them, as after all there is likely a reason Thanos Quest and Infinity Gauntlet go on to make commentary on how and why the capacity of a mind truly determines the value of power, but Starlin's psychology and philosophy background suggests they're more a metaphor or moral.
After all they were transformed from simply being the mere 6 Soul Gems for a reason. I'd go into how each Gem was renamed to represent a facet of metaphysics, but that's a circlejerk for another time.
Instead I want to focus on their enigmatic presence. In Thanos Quest there's a pattern where most of the Elders, and the Inbetweener, held one particular gem that reflected or complemented their personality or beliefs in some fashion or would prove useful to them were they aware of it. In dormant hands they are dormant, in dangerous hands they are dangerous. The fact they're in certin hands at all gives the impression there's an ominous nature to them and Adam Warlock all but admits as much when he alludes to what his connection to the Soul Gem has uncovered.
Similarly Thanos meditating through the Infinity Well and gaining insight into the origin of the gems produced similar information about the Gems once being a singular entity, a concept taken to its questionably executed conclusion with Nemesis, but that later matter is unlikely to get involved in MCU.
As for the rest I hope Strange is well received enough so come the whole Infinity affair Marvel is willing to be a little more thoughtful about adapting Starlin's full intentions with the Infinity Gems and not just the impression people get.