I know what you mean but if I wanna destroy another one phone using my app, I can post the fake source code and publish the another one, right? So it's all about the credit.
Search my name "Sittiphol Phanvilai" using google or any search engine and you will see who I am and how trust I am.
Cheers,
I wouldn't trust my mom's binary if it asks me for a root password.
If we have the source code, we can make sure it doesn't have bad stuff in it, and compile our own binaries.