This is an interesting topic. Initially, when I thought about this I was kind of bummed- "Why doesn't HK/FN/Beretta make a 1911? They make great guns otherwise...?
Then I remembered this: http://cheaperthandirt.com/blog/?p=20180
This was for April fools day from this year... Glock making a 1911 just seems bizarre, right? Or maybe it doesn't, YMMV.
Not to say that these companies couldn't make a fine 1911, but their style is just a little different, and I'm fine with that. I love my HK, but the thought of an HK 1911 is just weird for me. To each their own, I suppose.