If I should guess, I'd say the offline installers are generally "discouraged".
From the past experience, people tend to store them and use them for some time - and then they're installing an obsolete version. Not only it doesn't provide a full protection from the start, but in between a Windows update may have been released and the older version may crash on the new OS, or even bluescreen the whole machine (i.e. the machine may not live long enough to download the update). Or there may be a false alarm on a system file (that didn't exist at the time the offline installer was built) - and it manifests before the program or virus definitions are updated and breaks something.
On the other hand, if the installer is not stored for long but only used for one installation, then it's an unnecessarily big download (the offline installer contains stuff that won't be installed on your machine, e.g. it has both 32bit and 64bit versions of the program, i.e. everything is at least doubled).
I'm not saying an offline installer is not a good thing in specific scenarios - but they don't happen for the vast majority of users. So that's why the links are kinda hidden (IMHO).