Application sandboxes are an essential security mechanism to contain malware, but are seldom used on desktops. To understand why this is the case, we interviewed 13 expert users about app appropriation decisions they made on their desktop computers. We collected 201 statements about app appropriation decisions. Our value-sensitive empirical analysis of the interviews revealed that (a) security played a very minor role in app appropriation; (b) users valued plugins that support their productivity; (c) users may abandon apps that remove a feature – especially when a feature was blocked for security reasons. Our expert desktop users valued a stable user experience and flexibility, and are unwilling to sacrifice those for better security. We conclude that sandboxing – as currently implemented – is unlikely to be voluntarily adopted, especially by expert users. For sandboxing to become a desirable security mechanism, they must first accommodate plugins and features widely found in popular desktop apps