1. Microsoft deserves the control of the development on MS Office, i.e., I
hope (for Microsoft) that this development only happens with software that
Microsoft controls. In the same way, the user of MS Office deserves the
control of the work she achieves with Microsoft office. An editing work this
time, not a development work. With MS Office, she does not have this control
over her own work. Microsoft controls the software and, through the software,
controls the user. That is not right. Developing proprietary software is not
right.
2. On the contrary, a user of LibreOffice is in control of on her editing
work. She can use the program as she wishes (is MS Office's license still
prohibiting the use of the software to criticize Microsoft?), she can study
the source code to verify that the program does what she wishes (no spyware
for instance), she can modify the program so that it does what she wishes
(correct a bug for instance) and she can redistribute exact or modified
versions of the program to help her neighbor (MS Office's license attacks the
social solidarity).
3. You can't gives reasons to principles. By definition. Yet principles are
essential. They are the starting points of any argumentation.