There's a lot of enterprise stuff that only ships as binaries. I had some fun in the late 00s trying to find the most recent distribution still shipping packages for egcs as that was the only compiler supported by the Lotus Domino SDK.

(For the younger ones here: There was some disagreement about gcc development, which resulted in the egcs fork. It got merged back into mainline gcc by he late 90s already, though)

At the time when the Loki ports happened it was a great thing - before that you pretty much had doom and quake available. Nowadays things are better with steam, but it's quite likely that we'll see some stuff break there in a few years as well, at least for older games.