Helpful in the shortrun, worthless in the longrun.
It'll help to boost up your healing, mp5, and crit rating (to a lesser extent) pre-raiding. After a while though you'll get plate which is better than that cloth and now you have a profession which is mostly worthless to you except making spellthread for your new pants every once in a while.
You can do it though, there's no real clear cut "You have to have this profession" for a Paladin of any spec.