Unfortunately, the Mac App Store has other major issues that prevent publishers and users from using it. While sandboxing can prevent security issues like this

Unfortunately, the Mac App Store has other major issues that prevent publishers and users from using it. While sandboxing can prevent security issues like this, it also interferes with basic functionality of many apps like IDEs that use multiple files. Even VLC can't automatically open the associated subtitles file for a video you open. So, there are whole categories of apps that are a bad fit as they'll be hobbled in terms of user experience/functionality. Add to that the 30% take for Apple that cuts into the bottom line and isn't made up for by increased installs from the store, the inability to charge for new versions of apps which kills off long-term development funding, and the poor UI and bugginess of the store itself and it's clear why the vast majority developers don't use the Mac App Store and existing high-profile developers in the store have been exiting from it.