For what its worth, I try to get out to as many courses as possible, new and old. Never a course that I couldn't learn SOMETHING from, IHMO.
I seek out Faz, Doak, Dye, as well as other masters and near masters from the golden age until now.....in the corporate world, its called "benchmarking" and maybe the top guys won't admit they see other stuff because they need to promote that they are the benchmark others follow.
But I will tell you two things:
First, I am not a good enough marketeer to say every idea I ever had was original. As Dan Kelly can tell you, I go around the Quarry telling him (and others) that the I wouldn't have built the second hole if I hadn't seen Tobacco Road, the sixth if I hadn't seen the ridge running second at Sand Hills, the 14th without having played the Dell hole in Ireland, etc. It's not that any is a direct copy, but I got some "background" information of ways to handle certain situations should they ever arise.
Second, if Jack's sales pitch (or that of any PGA Pro) is that he has SEEN and played all the worlds great courses (and it usually is) then why is it a bad thing to see more courses now?
As to Faz, once his office asked for some photos of various ASGCA members work for some industry presentation. I sent in some of a par three with a design idiom I have used a few times - three clusters of either 2 or 3 bunkers around the green at a similar angle. When they called to thank me, they said it looked nice (also implying to me, BTW, that they were sort of surprised at the quality, but that is another story) The point of this story is that not long after, I saw a Faz course with a similar array of bunkers, albeit some grass and reversed from the photo. Could this picture of my work influence them? I can't prove it, but I (like to) think it did.
Any gca who looks around a bit sees how much good work there is out there, and how much better you have to be every project, just to stay even in this field. At least, thats my opinion. As Mr. T might have said, "I pity da fool who don't look around at other golf courses!"