Meringue puts it very well.
Previously, there were plenty of men who were charged more because more men made claims. Some said it was because women were safer/more cautious drivers and some cited the fact that, on average, men drive more miles per year. Nevertheless, an individual 60yo man who had never claimed was no more or less a proven risk than an individual 60yo woman who had also never claimed; however, because more other men had proven themselves to be a risk than other women, he was charged more.
The occupation question is an interesting one. Usually, stating that you're 'unemployed' hikes your premium, ostensibly because you could be driving all day whilst full-time employed people are at their workplace. Obviously completely ignoring the fact that you're much less likely to be driving in busy rush-hour traffic and that, if you have less money, being unemployed, you can't afford to buy nearly as much petrol/diesel, so may be driving very seldom anyway.
Entertainers - especially TV celebrities - tend to be charged a fortune. This might be skewed by the fact that they can afford much more expensive cars than the average person. They might also have to drive more defensively to escape the Paparazzi or crazed fans - or have people target their homes to steal their cars when they're on live TV or are featured in the press putting on a VERY busty display and showcasing their endless pins on the beach in Malibu on their family holidays, who knows?
IIRC, the people who get whacked with the highest premiums at all are those with 'dangerous' jobs such as stuntmen or professional extreme sportspeople - even though they don't actually use a vehicle whilst doing their jobs and, one could argue, they are probably more aware of the need to take precautions and be more risk-averse than a teacher or a plumber.
Statistics do mean that you get lumped in with others who share one or more relatively minor characteristics or life circumstances with you. It's essentially endorsing stereotypes and, you could quite reasonably suggest, perpetuating discrimination.
It's just statistics, though. Right or wrong, you can see the thinking in it - how many people would run at the sight of an escaped lion but not upon seeing a pigeon, even though neither that lion nor that pigeon has (yet) ever done them any harm? - but the only alternative to statistical risk-based pricing would be to charge every driver exactly the same, regardless of age, experience, claims record, location, vehicle type/power/age etc.