Its pretty decent, not the top #1 money maker (farming the right mobs would be more efficient), but you can only quest/farm mobs for so long. At least I get bored. Fishing is a fun way to unwind for me, and getting a stack of fish that sells for 19 gold is pretty darn nice. And now my fishing is a bit higher, I'm sitting at 356 now hoping to hit 375 in a few more days. So I can finally fish the golden darters effectively, and soon I'll be fishing primal water, and the spell dmg buff fish.
If you hate fishing, I wouldnt bother. If you enjoy it to unwind, its quite profitable at a very high skill level. I'm not sure how this upcoming 2.1 patch will change that, I wonder how many new people will decide to level fishing now?