my Sims use a sink to prepare food instead of the counter

Mine do this too. I do not use MOO when placing the counters, cupboards, or tables and chairs. I'm not sure why they do it. It only seems to be the "salads" that go in the bowls.. SO fruit salad (almost every single time) and the "regular salad" (sometimes)

I find its more of an annoyance than anything else, as it takes time to walk back and forth, and usually my Sims need to eat, and go to work.. and when they're walking all over the house, they waste that time and don't get to finish their meals. :(