Pratt, who met Montag while starring in MTV's The Hills, told The Daily Beast that while the pair initially hoped to build a career from the show, they eventually discovered that such a thing is not feasible as fame resulting from reality TV does not last forever.
Pratt said: "This isn't a business. That was the big thing I didn't get: Reality TV is not a career. Anyone who says, 'Oh, you can have a career in reality' - that is a lie.
"We were all getting paid to be people we weren't for so long that you stop - there's no line. The gauge is gone. The grey area is gone."
Pratt also claimed that he and Montag staged their break up last year in the hopes of revamping their popularity as public figures.
"At that point, we were pulling our last cards. We felt the hot air balloon losing its gas. And at that stage, our income would be selling the photo that would go along with the divorce," he recalled.
Pratt and Montag renewed their wedding vows in November 2010.
Montag will be seen this fall on the new VH1 competition series Famous Food.