The people whose lives are being ruined by Airbnb

The people whose lives are being "ruined" are those who can't get a home because the housing stock is being converted into part time rental and those who thought they were living in a residential zone but who have permanent part-time housing nearby.

(those who live next door to a neighbor who rents out the place once in a while aren't having their lives "ruined").

You can say it's fair or unfair or simply the way of the market but this kind of disruptive turmoil can run peoples' lives. The buggy whip makers' children had to suffer unless the buggy whip makers diversified too.

Personally I have sympathy for the people in my first paragraph above. For hotels in general...less so.

lives are being ruined? hardly.

They now have competition. This happens in almost every industry. You either need to learn how to compete, or you will quickly be out of business.