At least from a perception perspective that's all true, but I don't necessarily agree that it's right. An agreeing example to highlight why I disagree:
I just performed a risk analysis of an industrial campus electrical system in Puerto Rico. Failures are scored according to severity and likelihood, with full power outages for more than a day getting the same, maximum score. Below a day, outages or voltage dips ranging from miliseconds (can often be plowed-through) to seconds (it takes 30 seconds for a generator to start) to minutes (it can take a few minutes to reset a tripped circuit breaker) have different severities.
Hurricane Maria, however, was an unprecedented emergency situation, and generators that were designed to run for hundreds of hours a year instead ran for thousands last year. This requires a new level of "severity" not previously considered.
Unlike power outages, which are not all the same severity despite looking the same at the moment they happen, a death is a death. They are all the same. And in a country where individual rights are paramount, they are all weighed equally. So a fair risk assessment should say that a plane crash that kills 150 people is exactly equal to 50 car crashes that each kill 3. And multiplying that by the probability of each gives the relative risk.
...though "probability" is not clear-cut because the transportation is used in different ways/for different purposes and as such there are different choices that can be made for the measurement in some cases. I can consistently compare miles or trips to make a decision on how to get from Philly to Boston (and get different answers if I use "miles" or "trips"), but I can't really compare them for a flight to San Juan, since you can't drive there. That makes direct comparison a little tough.
