Why would a professor assign more grades to a presentation than a report in a software engineering subject?
Presentations generally involve a discussion with the panel, questions from the audience, and even heated debates.  Papers present the research and can absolutely give an impression of the knowledge of the writer, however, it can be easy to hide behind a paper.  You can't hide in a presentation.  It becomes quickly, and sometimes painfully, obvious in a presentation when the researcher has not fully developed their work.

Also, very few people will take the time to read the paper, but there's a good chance that quite a few people will attend the presentation.  How well you present your work will reflect the quality of the work in the eyes of the audience.  It might be outstanding research, but if you can't present it well and your message is lost, the work will be shrugged off.