The more costly cars tend to have more customers who can go after the manufacturer for defects/headaches due to their typical higher income and possibly even being an attorney.
Two things. Higher end cars are bought by all ranges of income. Leasing today has leveled the affordability to a much larger income demographic. That new 7 series or E550 can just as likely be leased by someone making an average salary as it is a wall street lawyer. A case could also be made someone who can barely afford their car will be just as aggressive towards defects as a high income individual - not so sure Hyundai fears a buyer with a JD any more than any pissed of customer. Social media has helped level that playing field for the consumer.
Not sure why CarPlay has been stalled on the Genesis, but the percent of lower end cars Hyundai sells is in a more competitive and financially important environment where these features can be deal breakers. If the Honda Accord has it, the Sonata better. Bang for the buck makes those cars more of a priority than the slower selling Genesis. CarPlay is not yet shipping in Mercedes or BMW.