How do you build something good from something bad. Deconstruction? Cut out the bad? Does the bad run right through it or is the bad only slight?  

Firstly you can’t build on bad anything and bad doesn’t magically cease to exist. You can ignore it, pretend and hope it’ll go away, but that’s ignorance at play just adding to the bad. 

Options are what you have. You work or you walk. It’s not about what you gain or lose, it’s about what you’re willing  to risk. 
Risk is possibly the wrong word, but it works for me. 

It’s like knowing someone has done something really bad and then introducing them to your friends. You too then become bad.