These are all interesting assessments of Blender.  As a user, I both agree and disagree, of course, with how it is perceived by non-users.  Blender opens a new scene with a default cube, not a sphere, by the way.  The cube is widely known as the basic starting object for almost any model you wish to create in 3D, so that's why they chose it.  This is actually meant as a convenience to people just learning.  Once you become more used to the software, you can set it to open an empty scene in the preferences, and switch the mouse controls to work with left click instead of right click as well.  The only thing I think they need to change is the default right click.  Every software on the planet uses left click by default, even non-3D software, so it should be left click.  I think that alone would make it much easier to learn.