Non-native speaker here. What are the disadvantages of being straightforward? In my native language, it is considered more efficient and polite to be to the point. I have worked with Americans in the past, and I have noticed that they are not straightforward.
Being straightforward is fine, but often times being straightforward comes with an air of superiority. It's fine in a boss setting, but you should be careful giving commands to people who don't answer to you as it shows a lack of respect. People just want to be treated nicely and feel like they have a choice.