Hello
At least 4 reasons:
1 - Its the (almost) 100% academic market format;
2 - Its the (almost) 100% business market format;
3 - it’s going to be the archiving format for normal 2D (at least) documents - PDF/A ISO standard 19005-1 (more info
http://en.wikipedia.org/wiki/PDF/A);
4 - it’s very easy to create - throw a bunch of images to a pdf file and almost every pdf reader will let you see it as an identity.
Note: PDF is not going to be away, expect the contrary.
Best regards,