Ah, kitchen sinks. For many years I didn't use a bowl as my sink was quite small. However, when I had a refurb the sink was bigger and I now do use a bowl. A bigger sink uses more water and we're on a water meter. As Helen says, you can use the water in the garden, or to chuck down the waste disposal. Also, you don't damage the sink with the cutlery or break crockery if you drop it. You can also rinse the washing up down the side of the bowl, thus keeping the water clean for longer. All in all, I prefer a bowl, although I know this is an emotive subject. 
Off to watch the last ever episode of Ripper Street. 