Your comment is exactly what OP is talking about. The article is about credibility, not the role of individual choice. Obviously climate change is bigger than rich people going on vacations. Neither the article nor OP disputes this.

The point you're missing is that people who advocate for sweeping policy change - the sort that will require people to drastically change their lifestyles, as well as drastically changing the way human industry operates - are more likely to be taken seriously when they change their lifestyles in advance.