Actually, what I wanted to say was,
Because this site doesn't have your password encrypted with some algorithms like SHA-256, if the site is hacked, the hacker can read your password like a text file. The proof is the passwords sent by email when you click 'forgot password'. It is not possible if the site encrypts your password.
So, It doesn't matter how strong you make a password. It will be leaked if the site is haked.