I said "want to", and I meant "want to". I don't consider it pedantry - Everyone has a choice.

• People looking to buy their first car (or replace a junker) can either get an SUV, or a sedan. This legislation tips their decision.
• People who own a car (because they live in an area that needs it) that happens to be an SUV, and are then planning to go into Paris, can choose to instead drive to a local train station, and make the rest of their trip using local means.
• People who live inside of Paris can choose not to buy a car at all; or just stop using the SUV they bought earlier after deciding it was a bad fit for their area.

There's perhaps a fringe case of people that can afford two cars, own one SUV, and still insist on driving into the city - whether that means stomaching the fee, or buying a second car. That is very much a "want", one that increasingly dense cities cannot easily cater to. I'd even say there's not a huge demographic of people who could decide to buy a second car purely for this situation.