I see Grargar already linked to the post I made earlier, so that part has been taken care of.
It's possible that the reddit poster had not noticed that they were listed under "Game Goodies" at some point.
As for support's reply, it's possible that we're seeing an overly eager to promote Galaxy GOG staffer, or the GOG employ takes it for granted that everyone and their cat are using Galaxy, or they have instructions to promote the use of Galaxy.
Whatever the case, they should have stated that downloading is very much possible via the browser, and omitting it does make a bad impression.
On a side note - the DLC downloads are mislabelled on the GOG Downloader page.
Grargar: False alarm.
Edit: Since direct linking doesn't work, I have also attached a screenshot with the relevant post.
This one works just fine for me.
Edit: Leaving enough space after the first part of my post, does not.