People aren't generally opposed to the idea of differential algorithmic pricing, they're against the way it'll almost inevitably get implemented if allowed to be done without regulation / public involvement and oversight.
Ask a lefty if they're in favour of charging people fines based on net worth/income, rather than based on a flat rate. Speeding ticket? That'll be 0.5% of your annual salary, or 0.5% of your net worth, or a baseline minimum amount, whatever's higher.
The way it'll get implemented though, is more like "It's hot, so you gotta pay x2 for water if you're poor already". And "you're a privileged race/gender, you get X pricing, it's not discrimination if it's an algorithm doing it!".