If you'd ever tried to cross the road at that roundabout, the bigger traffic island will be appreciated. Please think of others, such as elderly people that can't move very fast or mums with prams etc.
I was in town, yesterday, from 0830 until the afternoon, and Dave's comment struck home rather forcibly. At one point we'd parked in the Big Mostyn C's car park, in the quietest patch, about mid-car park, having navigated the totally unsuitable mini-roundabout at Staples, and we had to walk across the road to B & Q. With cars arriving from left and right, and cars leaving in the same directions from both car parks, what should have been a relatively simple stroll evolved into a nightmare of dodging, weaving and - at one particularly memorable point - standing in the middle of the road, simply because had we waited for the road to become totally clear, we'd still have been there, I suspect.
At the very least, a crossing is needed between the two car parks, although some form of bridge would be preferable.