Boingboing is a news blog as well as a “wonderful things” blog. You’ll note the tagline change to “mostly wonderful” things. The Authors post what interests them, and that currently includes non-wonderful news.
The thing is, it’s not a “format change” - the Authors have always posted what they want - what you are asking for - for a blog where only a loose definition of “wonderful things” are posted - would actually be a change from how it’s always been.
Might I recommend the Good News Network if you’d like to not read about bad things?
