There's an important point buried in here - AppBrain and similar is something that is allowed and encouraged on Android, whereas any app that duplicated or encr

There's an important point buried in here - AppBrain and similar is something that is allowed and encouraged on Android, whereas any app that duplicated or encroached upon market functionality would not be allowed on iOS. If AppBrain or similar takes off, Google can just buy them and roll it into Android - an easy win for them. By allowing others to come up with these systems, Google are effectively allowing Natural Selection to produce the best App search system.