Yes, it's unfortunate, but it does make sense.
The free version of SketchUp is so powerful that there needs to be some way to distinguish the pro version from the free version or nobody would drop 500 clams for the pro version.
For a more in-depth look at the difference between the free version and the pro versions of SketchUp, see the link below:
http://www.suwiki.org/suwiki/index.php?title=The_Differences_Between_SketchUp_Pro_and_Google_SketchUp
-abe.