The big problem with the deal is that it combines two brands that offer foods consumers simply don't desire anymore, Cramer said.
"When you put fast food together with doughnuts, what you end up with is exactly what our kids will not have," Cramer said on "Squawk on the Street," suggesting consumers prefer natural and organic options over fast food.
"The culture is changing worldwide ... these [are] brands that are out of sync with what millennials want," he said. "You can merge them all together. You can try to blow them out. And in the end, Burger King is [a] food chain and the food chain is viewed around the world as something you no longer want to be a part of," he said.
Read MoreBurger King deal: A tax dodge whopper?
"It's time to start focusing on the fundamentals, not the taxes," Cramer said. "Because you can make really, really good dog food commericals, and if the dogs won't eat it, who cares?"
Still, the merger got the backing of one of the investment world's biggest names: Berkshire Hathaway Chairman and CEO Warren Buffett is helping to fund the deal by committing $3 billion of preferred equity financing. The news release on the deal did not disclose the terms for Berkshire, which is only a financing source and will not have any participation in the management and operation of the business.
Read MoreBuffett greases $11B Burger King-Tim Hortons deal
"Warren Buffett is the winner here because he's probably going to make some money," Cramer said. "But the idea that we should endlessly pile into this stock, up another 8 percent today with the terms, you know what? Maybe we have to walk it back a little."
Cramer recommended investors "take profits" on Tim Hortons stock.
—By CNBC's Drew Sandholm. CNBC staff contributed to this report.
DISCLOSURE: When this story was published, Cramer's charitable trust did not own Berkshire Hathaway, Burger King Worldwide, Starbucks or Tim Hortons.