It's because Musk sniffs his own farts and has bullshitted his way into more and more money his entire life. He wanted to morph Twitter into the platform he wanted, but also tried to make it net a profit, by 1) fucking over people/companies to whom he owed money, and 2) trying to squeeze money out of users who had used the platform for free for over a decade.
He's one of those asshole kids who start bum fights, but he's trying to get the bums to pay him for participating and he's not paying out to the bettors who won.
It's a play on the phrase "Well-behaved women seldom make history" which comes from a 2007 book by the historian Laurel Ulrich. Because no one read the book for the context, the quote itself became popular, taking on different meanings based on however individuals choose to represent it.
When it was added to the lexicon of basic white girls, it naturally became productized into shirts, mugs, neon signs, etc.