Playback of Blu-ray discs is by DRM (Digital Restrictions Management or euphemistically "Digital Rights Management") when the monitor and PC are connected via VGA or analog video output. As unusual as it may seem one to want to play Blu-rays per analog video output, it should be mentioned here yet.
However, the "blame" for this is certainly not to look at the manufacturer of the software, but rather in the Blu-ray Disc Association and probably the problem occurs with all other versions that can play Blu-ray and even with the appropriate software from other manufacturers.