Buying packs and intentionally not using the main feature

I buy only the packs I know I will use a lot. There are some packs I'm considering buying where I will use some of the features, but not all. These ones I will get at 50% off, if I do decide to get them.
I don't see any problem with people buying a pack they won't use the main feature so long as they recognise that they got it for that small feature in it and don't complain about it being "not worth expansion pack price" and try to demand the devs change a game that others have gotten for the current main features and enjoy.