One of the defenses for the "abandonware" scene has been that the old games are hard if not impossible to buy legally anymore. This was especially true for the classic adventure games from LucasArts and Sierra, who presumably saw the genre as dead and didn't bother to keep the older titles available.

The other issue with play old games in their original format is the lengths one must go to for them to run properly; often involving throttling CPU speed, running a DOS emulator, and/or using a special launcher. But now VU Games (which now owns Sierra Entertainment) is planning to release compilation packs for several of Sierra's popular old adventure series, such as Space Quest, King's Quest, and Police Quest. It's unknown at the moment what games will be included in each pack, but the packs will cost $20 each and will be programmed to run on Windows XP without the aid of extra programs.

Source: Gamespot