pros and cons

“Pro” is a full word. It is borrowed from the Latin preposition pro, which means “for”.
“Con” is also a full word. It comes from the Latin preposition contra, which means “against”.
When we consider the pros and cons of something, we are considering the arguments for it, and against it.
“Con” meaning “against” should not be confused with other meanings of “con”, which have a different etymology, and mean entirely different things. Most of them involve the Latin prefix con- (from cum, “with”).
--- 摘抄自Quora
More pros than cons 利大于弊

大意就是Pro和Con都是沿袭于拉丁词汇，Pro 意思是 for something（对...好），Con 意思是 against something （对...不好）