Both of those were business trips. My vacation travel is different: I have a wife and 3 kids, so it's almost impossible for the five of us to stay in someone's private residence. For those trips, I look for places where the owner only has one property, which to my mind indicates they give it--and my family--a high level of personal attention. Sometimes it's a cottage in their backyard, like the ones I've stayed in at Tahoe and Pescadero. Those a nice because I can meet the owner and they're just 20 feet away when I need help. I am also an Airbnb host of a cottage in my own backyard. It's booked about 90% of the time but the neighbors on my street tell me they usually forget I'm even hosting because they don't even notice.
But there are hosts who manage many properties and there are guests who stay in them. I personally don't like the feeling of being tricked into thinking a place is owner-occupied and then finding out it's managed by a property manager, and I will say so in a review. (We have rules for employees; I won't look at our internal systems when booking to try to see more than the usual customer would see.)
The managed properties are more common in some large urban cities. That is why last year Airbnb banned owners of multiple properties in some large cities around the world. I honestly don't know the specifics of any one city such as Cologne, which is mentioned in the article.