Good point, but I still don't think abandonware is all bad. I've been a visitor to Abandonia almost since its beginnings. They've been pretty good about pulling games once the devs start attempting to sell them again (Betrayal at krondor comes to mind).
And hey, beleive it orn not, there have been cases where I had downloaded a game, only to have it start being sold again via GOG, and I bought it anyway (Lands of Lore for example).
Let's face it, many of the titles Abandonia has will likely NEVER appear on GOG or anyone else, for a myriad of reasons. For example, i don't know who owns the rights to the Legend games, like Shannara, so they may never appear here. So I've gotten them from Abandonia. But if they do appear here I'd likely buy them, not only out of morality, but because GOG titles are usually pre configured and I can easily move them between computers.