tar somebody/something with the same brush

tar (someone or something) with the same brush

To unfairly categorize someone or something as being the same as another person or thing, usually in a negative manner. Just because the CEO turned out to be a rotten scoundrel doesn't mean we should tar the entire company with the same brush. There is absolutely a segment of video game enthusiasts who create a hostile and toxic environment online, but tarring all gamers with the same brush does a disservice to the community.
See also: brush, same, tar

tar somebody/something with the same ˈbrush

judge a whole group of people or things unfairly because of your bad experience with one or a few of them: Because his older brother had been a troublemaker at the school, Paul was automatically tarred with the same brush. It wasn’t fair!