Well, strategically, they might eventually want to think about making some return on investment for the acquiring investors with actual cash profit. Otherwise, they will eventually be shed at a loss (is anyone else here old enough to remember AOL and Time Warner?).
Strategically, they may also be serving as a cautionary example of why start-ups without a secure revenue model shouldn't be acquired at all, unless there is financial upside for the investors. After all, the article further reports, "Reddit is not an exception to every rule in the digital world. Like many digital media companies, it has a big audience and minuscule revenue."