Op from my own little knowledge use of a long seedphase mean it can't be easily hacked by attackers to break most at time using an simple password or short phase can give an dictionary attacker easier access but using longer phase make it more harder to break through, what you should understand is that the complex and longer the seedphase the harder it easier get access to by attackers Many people have fallen into this trape and it has lost them there wallet been hack all in the name of I don't like using long password or seedphase. most people like to use personals information to create passcodes this can lead to a ease attack.