I mean, I agree with both sides here. On one hand, it absolutely has more gameplay on the technical side. There is the full 10 tier knitting skill that creates unlockable clothes and items. Plus a new way to sell with plopsy, a new thing to teach kids, a bunch of crosspack stuff, and rocking chairs which have one unique interaction for elders. In comparison to previously mentioned Luxury Party Stuff, it seems like a whole lot more than a buffet table and fountain. At the technical level, though.
Nifty Knitting is so narrow in its focus that it is fairly difficult to use without deliberate intentions. To make use of that $10 you have to play knitting Sims. In comparison to Luxury Party, I need only set party/formal outfits and place a fountain or buffet table. I find myself using bits and pieces of LP, Backyard, Movie Hangout, and Romantic Garden Stuff all the time without intentionally doing so. Partially due to the lack of gameplay entry and the more broad focus. Have a yard? Guess what, Backyard, MH, and RG can fill it and doll up your Sims, too. Need a formal or party outfit and want to have an event? LP has you covered.
Broader themes allow for broader usage, and in that sense stuff packs that are broader have more gameplay-- Though perhaps mileage is a better term. You can use it all, of course, but be honest: if you do not have a single knitter in your family, how much can you use the pack?