Given the considerable number of Sims players that buy every single bit of content that is released for the Sims, I can relate to the cash grab argument.
Also, the only kit that contains new gameplay has - in my humble opinion - some severe bugs and is not properly thought through. I feel they really should have taken more reference to how doing laundry works in TS4.
I do find the kitchen set really beautiful and my daughter begs me to get it, but I'm of the opinion that it has not enough content to make it worth the current price tag. There's not even a matching dining table, chair, dishwasher and barstool.
The third kit is even more lackluster, but luckily not my cup of tea at all so I don't care about that one for now.