Do I really need to waist my time on link building?

If your links aren't showing up in webmaster tools then you need to build more links to them. Also it could be the case where you don't have enough link diversity. If you don't have other strong links, your article links won't show up.

Good content that attracts links is hard to come by and takes time. If you want to do something spectacular like make a movie or deadlift 1500 lbs or something really difficult then yeah you can get natural links.