This is the subject of an interesting thread on the debian-devel mailing list.
It started with ".. The current policy of hiding other versions of Debian is limiting the adoption of your OS by people like me.."
It seems that this user managed to contact us developers and give us some important information how we can improve the user experience. The following discussion shows that all our users need non-free firmware to get their wireless network cards run.
Do we provide such installation images for our users?
Sure. We build them regularly, host them on our servers, we also sign the hash sum with our official signing key. But we hide them very well and still call them unofficial. Why? I would like to have a more positive name for those images. Ubuntu has the HWE (Hardware Enablement) kernel. Maybe Debian firmware enablement images?
We should better promote the images that fits best for our users.
BTW, the URL for all these useful images is https://cdimage.debian.org/cdimage/unofficial/non-free/images-including-firmware/
Since I'm not using the Debian installer or live image often, I thought my own installation tool would already do better. In FAI , I install the package firmware-linux-nonfree if I need some nonfree firmware. But it appears that this package does not depend on any WiFi firmware package. Oops. So, I've filed a bug report #980758 and propose to add another meta package that depends on a list of firmware packages for WiFi cards.
I've now added a workaround to the FAIme service. You can now generate fully automated customized installation images including nonfree firmware for the stable and testing release. The stable release images can also use a newer kernel and firmware from backports. All other package are still from stable. Another useful image variant in my opinion.