I wanna see this guys awesome contribution to software in code. We all know and have seen Carmacks code in public. What has this guy written in public. If his master piece is closed source, better not to put him on a pedestal.
He has a stage, not a pedestal. As with most things people say you should keep an open mind and decide for yourself what the value is of what they are saying.
There are plenty of well known figures which have only created closed source stuff. Take Dave Cutler for example of Windows NT fame.
You'll have to admit it's easier to grasp/grok someone's philosophy when they show code as examples. Kevlin Henney for instance is not as known as Martin Fowler, but illustrates clearly his points with code examples. I don't say Martin Fowler and Dave Cutler are not worth recognition, but the abstraction level needed to comprehend them from the bottom up is too high that you can't clearly see what they are talking about _unless you've been there_
That's the feeling I get when I hear them