I wouldn't recommend making rerolling your second job, nor spending more time rerolling than you do playing. But if your goal is to do Advent Ragnaroks and high-level Accessory Quests, you're going to have to invest time in rerolling or money in SSR kamihime / Miracle Tickets, and a little of both will yield better results than either alone. It all comes down to what you want out of the game, how far along you are in progression, and how satisfied you are with your current account. If the thought of starting over makes your stomach churn, then perhaps rerolling would make you like the game less, not more.