Facebook’s strengthening grip over its acquired properties has forced out more senior executives. It happened at WhatsApp in April and the directives have been more concerned with profit growth. Now it’s Instagram.

Co-founders Kevin Systrom, the chief executive, and Mike Krieger, the chief technology officer, released a joint statement regarding their departure.

We’re planning on taking some time off to explore our curiosity and creativity again. Building new things requires that we step back, understand what inspires us and match that with what the world needs; that’s what we plan to do.

The Wall Street Journal reports from sources inside the company that staffers were taken aback about the announcement and are now speculating about how two of the strongest stalwarts of Instagram’s community-focused internal culture. Recently, some of Facebook’s units have started overriding Instagram’s operations.

Krieger and Systrom seemed to have the same disagreements with Facebook management as WhatsApp’s co-founders Jan Koum and Brian Acton did: the subsidiaries were being pressured to increase revenues. One of the possible stalemates that has developed in the past months is a rumored Instagram-based shopping app.

Facebook CEO Mark Zuckerburg and other officials in that company who have been arguing with Systrom and Krieger were preparing for their departure. However, it has not announced replacements for the two.