There's only one sofa type with many colours.
Nonetheless, all this modular programming is something that can be used over and over again in multiple packs both future and past (if EA could be relied upon to make any changes to sofas in past packs or for that matter in the Base Game), and by extension did not need to be the job of the Game Pack guys.
I can appreciate that each piece has to be made. I can, unfortunately, see that having many modular sofas will cut back on how many actual objects we can have in a pack. That includes decor, clothes, and functional objects - and gameplay in general. EA is probably waiting for people to buy DHD before they give us a base game modular Sofa. Modular sofas look nice but are very inefficient.
Considering we got sideboard and cabinets in Country Kitchen, my Psychic Brain of Psychicness predicts that we'll get more modular sofas in future Kit Packs.