The risk factor involved in manned space missions versus a trip to the grocery store has got to be huge orders of magnitude in difference. This is an unfair, and frankly, useless comparison.
>if our choice was to explore the Solar System with a vehicle no safer than the Soyuz or to stay at home the choice has to be to explore, every time.
This is where I can't agree. You have to define "explore" - i.e. the particular objective of that flight on a case by case basis - and ask if it really warrants sending a human being up to do that job. Yes? Then by all means. Do it. No? Then find a safer alternative that accomplishes the same goal and that sheds the challenges of keeping a human being alive in a truly hostile and unforgiving environment. Also, I wouldn't consider sending an autonomous vehicle out to explore as "staying at home".
I get the emotional appeal... I just don't think it's rational for every case unless we really need a human's capabilities in space.