I don't see why new programmers need to read it. When I read it first time, I didn't understand what it really talks about. I thought it is about the difference between open source and closed source.
In fact, the book is about the difference between development models of open source projects. Cathedral is not necessarily a closed source project. When the book was written, Emacs, nethack and other open source software were cathedrals in a sense that core team developed software in private and released "tarballs" from time to time. Now, most new programmers don't even have such projects around. The first thing they see is GitHub, where forking a project is one click away. Even *BSD systems made their version control systems open for everyone.
Programming culture has assimilated superior development model and there is no way back. New programmers don't even imagine that developing open source software is possible in cycles of gathering patches and releasing tarballs, like the GNU project did before.