Yeah, in many ways that would make more sense. For one thing, the sun is likelier to shine during the day, so PV electricity can go into your car.
Unfortunately, the practical reality is that at home you're likely to have a garage where you can charge (though I'm of course aware that many people don't!) while at work your car is likely to be in a large parking lot without outlets.
The logical conclusion is that we should invest in widespread outlet infrastructure in pretty much all parking lots. We're just not there yet, which is why I phrased my first comment in the way I did.