I like that TS4 opened up a few rabbit holes from TS3, like the restaurant or spa. What I don't really need are open grocery stores and the likes, just because I personally would be really bored by watching my sim going to the grocery store every week to buy their food. If it was an option and we would still be able to just purchase directly from the fridge, it would be fine by me, but if you would literally run out of food without buying it at the store, no thanks. I know it's supposed to be a "life simulator", but this doesn't mean every single mundane part of life has to be in it.
I am also not a huge fan of active careers, to be honest. I know many people would like to see more of them, but I personally prefer to just send my sims off alone and I am really disappointed that you have to join your sim on their job in atleast some of the active careers to even get a promotion.
All in all, I like rabbit holes for careers, grocery and book stores and the likes. More "exciting" things like restaurants or arcades should be open though.