A recent idea I had for a novella to write at some point involves exploring a high concept; what would happen if you could replace a dead loved one that parted with you bad terms?
I'm expressly using fantasy as a vehicle for this; making it so the grieving woman is a mage capable of summoning naive, shapeshifting 'daemons' that will do as she commands. She commands it to transform into her sister, who was in life an aspiring musician whose final words she heard from her living sister were 'You'll never play at a concert, because you're terrible', or words to that effect.
The resulting consequences involve the mage sister swinging between taking hollow comfort in her replacement sister and becoming blameful and angry at the daemon for 'defiling her memory', and ultimately dying alone and bitter because she never naturally allowed for the stages of grief.
I don't know if it's that high concept with regards to literature as a whole, but for fantasy, it's a tad on the artsy side in terms of thematic richness. My question is thus:
Are there some concepts too 'highbrow' or 'literary' for genre fiction such as fantasy? Is the prospect of rescuing fantasy from the low-concept ghetto it's trapped in feasible? Worthwhile? Would any critics buy the attempt, regardless of the content? It is fantasy, after all.
Edit: To clarify, I myself don't consider fantasy deserving of the ghetto, I'm simply noting the trend of fantasy being looked down upon in the critical community, and its effects on a writer trying to get published. Sci-fi writers who attempt more human concepts (as opposed to exploring technologies and the cosmos) often relabel their genre to 'speculative fiction', and fantasy often does the same, rebranding to 'supernatural', 'horror', et cetera.