Personally, I very rarely bother with gathering. I can see how it would be beneficial (especially if you're selling shards), but it's so much quicker and easier to just buy what you need on the market.
As for crafting, I leveled CUL to 50 because I enjoyed it, and because I like to make a little Gil from it. But the crafting itself was a joy. Gathering is not so. It's boring and repetitive. I'm sure the same can be said for crafting, but at least with that, I don't have to run around from one tree or stone to another. I can craft wherever I want and not have to move around too much. I know that sounds lazy, but crafting is something I like to do whilst relaxing.
I like to be able to just blonk my lalafell butt wherever and enjoy the scenery, and/or chat without having to worry about running off here and there every few seconds.