If your primary concern is being able to effectively turn a profit and make gil by crafting, then it likely isn't worth it for you, unless you're such a prolific crafter that you are singlehandedly meeting your entire server's demand for crafted goods under your chosen three specializations.
However if you're more about self-sufficiency than profitability, and you'd rather put yourself in a situation where you can easily get every craftable item that you'd want even without having a massive stockpile of gil, it can be very worth the time and effort you'll put into it.
If you want to make more gil: Just craft more.
If you want to never even need gil: Make some alts, and cover every specialization yourself.
