Since the speed of light can't be exceeded (at least for now), it's a useful limit to put in place if you were designing a simulation. It means we can't escape various sandboxes and if we could exceed this limit, we could explore everything really quickly and the 'game' would get boring and there would be no point. It's as if the speed of light limitation is <i>by design</i> so we don't get to experience everything all at once.