for the love of the game

Used to explain preforming an action either out of true love for the subject or (used sarcastically) out of stupidity.

Sarcasm

"Dude, he just wasted wasted his one life!"
"He did it for the love of the game."

Truly
"Did you hear lebron donated 5m to YMCAs to build basketball courts?"

"He did it for the love of the game"