Consumers have the power to kill off a company if they feel that company no longer meets their needs. No company is immune.
If Nvidia continues to ignore their customer base for profits, the bottom will fall out and their competitors will fill the void.
GPU dominance varies between generations, so high prices will eventual fall with an underperforming product i.e. GTX 280.
Nvidia, AMD and Intel have all suffered after they achieved dominance and tried to charge a premium.
They aren’t ignoring their customer base though.