Back in Firelands with my former guild i raided 4 hrs a week and cleared 6/7 H, In DS we raided 6hrs and cleared 8/8H, i know it was easy but still. There are numerous guilds that raid 8-9hrs a week, which i still consider casual and are able to clear most if not all heroic content. So yeah..stop throwing the word causal as an excuse as you have other problems as to why you can't clear content.