Catching up with old threads , I know 5 years later! but you often see this question asked , the purpose of carriers is in their name , to carry things . They were not designed to carry infantry but to carry their heavy equipment mortars , hmg's , brens , ammunition, rations etc right up to the front line. They were very successfull in this role as they were small , fast , very low profile and hard to hit , and could travel almost anywhere a foot soldier could. Problems came when they were used for other things they weren't designed for.
In fact I reckon the infantry would be able to use a carrier platoon on the front line in Afghanistan today!