And my counter point is there are a great deal of games with a large replay value.
Morrowind, Oblivion, Skyrim
Never Winter Nights, Neverwinter Nights II
Baulder Gates, Baulder Gates II, Icewind Dale, Icewind Dale II
Shadowrun Returns
All of these games have had patches and mods. Some by the developer many by the community which have made these games last as long as they have. All of these games (Including Vampire the Masqurade Redemption and Bloodlines) I have in the box (except Shadowrun which does not have a box). I would not tell anyone to play any of these games wthout the patches (also known as the Vanillia state). Typically patches and mods add an extra scope to the game. Restores dialogue, makes things work in a better way. So in what way would you say playing an unfished game adds to the experience of a finished one? Yes playing a beta grants early access and helps find bugs, but it doesn't make the finished product more enjoyable.