Exactly. Linux is about flexibility. However, for the end user (and unless I read this article completely wrong, the article discusses software aimed at these people) to get something set up exactly how they want it, Linux doesn't make this an easy task to do quite yet. Like you said yourself, there's distro's aimed at different tasks.
Ideally (to me), some distro could have website that could autodetect hardware and have a bunch of {check, drop down, radial} boxes for software to put on it. (Want Fusion? OpenOffice? Gnome or KDE or XFCE or so on? How much information to see? Everything/Quick blurb/Errors only/Whatever else? Hell, if its for the end user, let them upload their own desktop background to use right away. Little things are important too) The site would then customize the distro and create the iso as needed for the individual.
That would in itself go a long way to creating a usable customizable OS that does what people want instead of trying to guess what they want and create yet another variation within the sea of distros. But, such a thing hasn't happened yet for a variety of reasons.
Just because I can customize a {Gentoo, Slackware, Debian, Red Hat, etc} install to be exactly how I need it, doesn't mean my neighbor who "heard about this lunix thing" can do the same.
"Different target market."
Which one are you discussing? And is it the same one as I am? I'm talking about end users.