I wouldn't chose to be a crafter for the 'advantages', but if you LIKE crafting, then it can be a useful skill to have.
Down side: Crafting takes time and money to lvl up in. You need to raws either by purchasing/harvesting. Crafting is slower to lvl the adventuring. Time spent crafting is time you are not out adventuring. You probably will not find many buyers if you try to sell app IV spells (or most other non-rare armour/weps etc). It's not impossible to find other crafters if you are even slightly social.
Up side: You don't have to search broker or LTW lists to find the item you 'need.' You can do writs to get status and exp. Due to exp boost to adventurers, more folks might be buying gear for their alts. It's something to do when you don't feel like hunting. Some adventure quest require harvesting or crafting skills. There are more crafting quest... including soon to be introduced quest for crafting GROUPS. There are Epic crafter quests as well as certain faction rewards and shiney collections (red shineys are found if you have an epic crafter earring).
I have 7 crafters, my hubby doesn't like it...either choice is valid (and any crafting class has pros & cons). It all really comes down to do YOU want to craft & that is hard for us to answer for you. Good luck.