Why not both? People choosing excessively large vehicles for aesthetics shouldn't get a pass because some giant company happens to produce the fuel it uses.
The concept of "carbon footprint" truly is corporate propaganda and deflection.
That does not imply that individuals are morally entitled to overconsume.
Blaming individuals may be interesting morally but it makes for terrible public policy. It doesn't produce anything actionable. Imagine trying to fix ozone depletion with a voluntary labelling scheme and "blaming" people who use CFCs.
AFAIK SUV sales replacing sedan sales is a trend that has been going on for decades[1]. Blaming it on "[car companies] don't want to put in the engineering effort" doesn't make sense.
[1] https://assets.bwbx.io/images/users/iqjWHBFdfxIU/iukk8bw9OXn...
Marketers and the US government.
Marketers and companies in general have enormous power to manipulate people and yet they dodge responsibilities all the time.