Believe it or not, A TON of people do it. I mean, the most common passwords on the internet are still words like "password", "123456", "abcdef" or stupid passwords like that. Who do you think uses them? People.
Well, the hackers definitely have billions of Yahoo account infos in a "box" somewhere. And I'm not "condemning those with alternative choice as low". Where have I done that? I'm just telling you you can do much better than Yahoo. Whether you listen or not is entirely up to you.
What does this even have to do with the topic?