It's ok. They will eventually come here. Eventually. Bigger fish to fry first. Many great games that are almost a decade old should be considered old by now. I'd rather have Ubisoft give us a sweet complete edition of Assassin's Creed II, drm-free and all that shabang.
While I do agree that really old games are what brought GOG to popularity, many of the most renowned franchises are already here. Now, unless more obscure titles present the possibility for high profitability given the effort that has to be put into bringing them here, with all that optimization and paperwork stuff needing to be dealt with, I would recommend GOG's administration to switch their focus to video games at least half a decade newer than the average on the present store.