price, determined by some intersection of supply and demand
high difficulty translates into
1) less coins rewarded per miner (greater distribution)
2) necessitates a higher price for them to break even on their investment (greater accumulation)
3) fiat that would've entered the mining space is now likelier to be spent buying bitcoins instead
4) restored equilibrium
and don't tell me that miners will panic or that they get coins for extremely cheap anyways because of mining. almost by definition they are in the long game, and anyways, the mining space is now becoming only viable for manufacturers
at the very least, increasing difficulty is a positive factor upon price to some degree. it might be lagged though
The point is - difficulty follows price. It's hard to justify the converse.