It’s very unfair to them as you don’t have any idea of what goes on in their lives outside of when your with them, and saying they disappoint you when they don’t even know about the standards you hold them to is just unreasonable. 

Instead of just looking down on other as they fail your expectations, humble yourself and help them and support them so they can become a better version of themselves that they want to be, not the version you want them to be