digital copies are forever.
cds wear out.
return to the website 20 years later? game's still there.
return to the cd? probably not in the best condition.
Actually, the reverse is often true. The past 12 months are full of DRM retailers who have gone out of business, taking peoples music collections with them.
And with the economy going the way it is, with people cutting back on luxuries like entertainment, I wouldnt be suprised if more followed.