Anaconda's comment about Digidesign's marketing campaign is right on the money.
Logic, which I believe is a very powerful program, still has the perception in the marketplace as a "complex tool for composition". Don't know if Apple intends this or not or where they're going with it. Pro Tools, on the other hand, has the perception as a "utility"...i.e. everyone needs it (this perception is overseas as well). I couldn't imagine a serious, commercial studio existing without Pro Tools.
As a Logic user, I've been reluctant to add Pro Tools to my own set up because:
a) I love the way Logic's proprietary plug-ins integrate with the application.
b) Powerful midi AND recording capabilities
c) Open architecture (i.e. it works with less expensive hardware).
While I do think there's a place for Pro Tools in my set up (don't know at what price), things keeping me from going there are:
a) General fear of plug ins (add'l cost and my own lack of knowledge about which ones are high quality)
b) LE or TDM....can't decide
c) Possible project maintance hell (i.e. I already have difficulty maintaining Logic files on my HD).