Without crafting/gathering, it surely is possible but it is not nearly as fast nor as much as you would with crafting/gathering.

Daily roulette's give quite a nice chunk of money(With needed class)
I know farming certain items from mobs can give you quite a bit of money, I used to make so much money with Fleece,Alumen and stuff like that. But that was prior to 3.0
Still there are quite some crafting items that are worth quite a bit of money, But you'll have to look around in the MB since prices flux quite a bit + Different servers and all.

But all in all, It still is faster too level all your craft classes 0->60 and then make money imho.

Spend 4 minutes crafting yesterday made 1.2M, Its very unlikely you will be able to reproduce that with farming items unless you get a minion drop or something similar