I'm sure the owner chose this format specifically so he could exploit threaded message views. Doesn't matter that its a sad, dated format going back to the days of USENET.
I haven't been on Internet discussion boards
that long, but that's the format that I commonly saw in 1997 and 1998. When one board - CapitolHillBlue Reader Rant - got hacked to Valhalla, their new SW was Ultimate Bulletin Board, and I loved its usability! The formatting tags I learned on UBB are used by more than a few different modern discussion board SW packages.