That’s sarcasm because their experience is BMW drivers not driving predictably or with turn signals. They were trying to add some snarky hate to BMW drivers because nothing in the article supported BMW drivers being a problem at all.
BMWs show up about 30% of the time in my notepad (in absolute numbers, not adjusted for how many BMWs are on the road here in the UK (5%)).
I would be shocked if BMWs (and Vauxhalls/Opel) aren't massively overrepresented in accident statistics here in the UK.