the weight limit went up for a few reasons, the main 2 being that very few machines are built to 100kg, and utilise the extra 2% allowance incase of scale error as extra weight limit. Therefore for robot wars they would all be over weight if we enforced the 100kg rule. Another reason is that the majority of live event robots applied for RW, and most of them have been designed around the same parts, shape, style as each other and for a TV show you need character and style as well as the functionality. This extra weight allowed people to make adjustments and improvements to their machine without having to start again with a very short time to do it in.