Wi-Fi can be a bit finicky, both with ensuring you have the right driver and configuration(there really ought to be a script that scans for available access points, presents a menu of the detected access points, and prompts for apassword if needed instead of having to either bake wi-fi networks into one's wpa_supplicant file or using one tool to scan and then another to connect that you have to type the name precisely as the scan reported without the benefit of tab completion), but ethernet should just work and never need configuration, even when switching between different Ethernet access points unless you get a bit overeager trimming a system down post-install.
And while part of me agrees that having things pre-installed and already configured is a big part of accessibility, both in the "blind people can use this" and "easy to use" senses of the word, I do think it worth mentioning that the Debian Unstable repositories contain over 63,000 packages, and that's not including the contrib and non-free repositories. Stable might have a little less, and over 11,000 of those 63,000 are in the lib and libdevel categories their are plenty of libs elsewhere in the repositories, and modularity means an application might be spread out over many packages(the version of Firefox I'm running depends on 32 packages, most of which probably have dependencies of their own), so the true number of available apps is much lower than the total number of packages, but there's only so much that can fit on a single CD/DVD, and only so many options a net installer can offer without overwhelming all but the most particular users, and its hard to hit that sweet spot where the installed system is lean but doesn't require manual configuration of basic things and is full-featured without being bloated with many packages most users will never use. Admittedly, "Just works" configuration of a computer's internet connection seems pretty darn basic, especially if you're using the net installer... but at the same time, the base system requiring manual configuration doesn't seem unreasonable and while it's been a while since I've done a clean install of vanilla Debian, I could imagine it being easier than it should be to miss whatever handles autoconfiguration of the network if you don't accept the defaults at the install additional packages step(which is probably most console users since I believe the default includes whichever Desktop came on your install disc(if using one of the variants of Debian CD1) or whichever desktop is Debian's default(if using the net installer or the DVD), especially since I recall some of the non-desktop options on the list of package bundles to install not being that self-explanatory.