Automated trading is better than manual trading?

Well, there's a saying "Plan your trade and trade your plan". Raymond Toh said in one of his articles "there's no way to make profit trading Forex (or achieving any success in any field) without firmly established rules and the discipline to obey them". You can not obey your rules if you trade manually, believe me: I tried manual trading and lost a lot of money. For the peace of your mind, you have to find a programmer and describe your manual practice to him, and he will give you back an Expert Advisor that makes your manual trading 100% automated!

MetaTrader and MQL4 give us the ability to write our Expert Advisors that simulate our manual trading, so, why don't we benefit from those great tools and make our trading live easier?