Tim O'Reilly on Mac OS X: "its tendency to hide affordances that were once a joy to the advanced user"

-- I think Tim nailed it there. Moves like making the Library file hidden are there for the growing user base of non-Power Users. Making that directory not easily accessible by default means people are less likely to break things if they don't know what they're doing.

If can be unhidden if you need it regularly, or you can get to it through the Finder Go To Folder menu. I found it puzzling that it was gone, initially, but I understand that the OS X audience is broadening and that we're going to see changes because of that. I think we're going to to have to go a very long way, however, before I see Windows or Linux as a better desktop or portable option.
It's not just that though (and that's not just OS X; Gnome is just as merrily dumbing down its interface and visible options); worse from Apple is abandoning not just power users but its traditional pro markets too. The New Apple is about nothing but pretty shiny appliances for the hard of thinking; not just hiding options, but removing them altogether.
I totally agree, my MacBook Pro is less intuative than my Powerbook G4. I can't find things now, which never happened on OSX10.4.

Especially the library file. That really bugged me.
Oh, and have you managed to make Zenmap work (or are you enough of a CLI wizard that nmap does for you :-) )