A good option because today’s users are easily distracted and forgetful, especially when it comes to remembering one of the hundreds of passwords they might have.
User Onboarding Spotlight: Why Yummly’s UX is Absolutely Delicious

Perhaps unintentionally, this sounds a bit condecending. Another perspective on why this is good app behaviour is that coercing users into adhering to certain password requirements usually ends up with me picking the simplest password that is accepted, or leaving. Second, it’s good because it is simply the only essential thing an app should need in order for a user to be able to subscribe to it.