1) Tesla is a stock market darling, so a lot of people have a lot of money riding on it. Some of those people may make different decisions with extra information they didn't have previously like the commonness of electrical fires. So we're not always talking about industry experts here. Could just be Joe Smoe software developer who plowed his equity grant into the stonk after vesting.
2) Tesla does market big battery packs to go in the home as well, which means this is a safety issue for people considering that. It's not like they are replacing existing battery packs and know the details. They are replacing either nothing or a diesel generator from Home Depot, so they may not be familiar with the advantages and disadvantages. Tesla doesn't have a good reason to be more forthcoming than is legally required either, leaving it to journalists.
So yeah, journalists just want eyeballs to sell ads to, but Tesla just wants to sell electric stuff. The latter has less reason to be truthful about the dangers.