Uniques have the same suspense as when you ID them, uniques can harbor powerful stats the same as runewords did (whats the difference between having a unique with teleport or it being on a runeword), choosing your base was a visual thing only really and you can transmog now so? Versatility again uniques can do the exact same thing, you can also just make certain uniques season only same for adding future uniques to fill itemization gaps (infact that is what they do), collected all the required items ehm... sets and lets face it you just traded for the runes you didn't exactly go on a long journey collecting them all? Not really sure what you mean by "manually forging" your putting runes into sockets, it's hardly anything more than just IDing an item.
Sticking rune combinations into then to make them. The suspense of seeing how it rolls after you stick the runes into place. The fact that runewords harbored some of the most powerful and original / game play changing items. (Enigma for teleport, etc..). The fact that you get to choose your base, so superior or crude base items actually made a difference. Versatility of common runewords early on during the leveling process. Different runewords featured for different seasons, incentive to play season, and differentiating 1 season from another. The adding of interesting future runewords to help fill itmlemization gaps. Giving the player a feeling that they have collected all of the required items, and manually forging your runeword rather than just gambling or forging at the blacksmith. I can go on and on if you want me to.
Pretty much everything you've said can also be applied to uniques. I see no difference at all between a unique and a runeword apart from the way you make the stats appear.