Well I'm in that 5%, and I own older cars mainly so I can still work on them myself.
My argument was that manufacturers should have to be clear up front with what they're selling. If 95% of the population doesn't care, and that means the market for maintainable cars isn't viable, why should I impose my will on everyone else? I'd like to buy a new car and be able to work on it but no company should be obligated to serve that desire.
You're being illogical. You'd only be 'imposing your will' on people if somebody preferred it being impossible to work on their car, which is obviously absurd. It's outright anti-customer behavior with no benefit to the customer whatsoever. It's akin to arguing that e.g. price fixing should be legal so long as a business informs the customer that prices are being rigged against them.
My argument was that manufacturers should have to be clear up front with what they're selling. If 95% of the population doesn't care, and that means the market for maintainable cars isn't viable, why should I impose my will on everyone else? I'd like to buy a new car and be able to work on it but no company should be obligated to serve that desire.