Rrriiiggght. People driving BMW's always stay in their cars or park them human attended parkinglots that take security seriously - if someone doesn't, then it usually results in keyed paint work, slashed tires or vomit in your car.
Everything you mentioned except the somewhat silly "attempt to hack the onboard systems [in a half hour]" is stuff that ICE luxury cars are just as subject to. Save for the possible novelty thrill of messing up an electric car vs. a combustion one, this risk isn't increased at all.
I said nothing about increased risk, I addressed the issue of the car being "safe" for the 30 minutes or longer that it takes to charge simply because "The charger cable locks into the charging port while the car is locked, so no one is going to mess with it while you're gone."
As for "novelty value and thrill" well, yes, it's stupid, pointless, and exactly the kind of dumb arse flash fad that has happened in the past and could well happen in the future - there's no logic to such things.
If there is no increased risk, then it is "safe" relative to the normal baseline for "safe" that most people would apply to a car. Pointing out that it is not safe in some unrealistic absolute sense is kind of pointless, don't you think?
It's like telling someone that a neighborhood he's thinking of moving into is unsafe without mentioning that your assessment based on the fact that the neighborhood is as likely as any other to get hit by a meteor. That doesn't qualify it as an "unsafe neighborhood" on the scale most people care about.
