Well they are correct to a point.
If the solar panel don't have grid failure shutdown for its inverter, it can shock (or with bad luck) kill workers working on a downed power line assuming the load side is safe. That is also why house installations also often only have a dedicated outlet during power loss and are not allowed to connect to the full house.
I agree everyone should be able to get off-grid solar system or balcony solar, but they should have to be certified to not shock workers during an outage when people inevitably get cheap TEMU balcony solar.