You've obviously never heard of small arcs haven't you? Most of the large and epic stories, start off with small shit. The plot is relatively simple, but what we've seen so far is what is basically the norm. Mages get sent on mission and kick ass. They come across bad guys who usually last for one arc. Why? Because coming across the same bad guy over and over again is fucking boring. Just look at Naraku!
That doesn't mean that there isn't a major villain. If you read Fairy Tail, you'd've known there was something up with Sieglein and Urtear.
Also, we've had some pretty major and epic stuff outside of the norm too. Fairy Tail vs. Phantom Lord for one. But since we're getting the arcs on each of the good guys out of the way, (Grey, Lucy(sorta), Erza), shit's gonna get epic in a matter of time. Bigger villains take time to make their entrance, but they always last.
And you forget. Fairy Tail is still in its double digits with chapters. In other words, you want the GOOD stuff, you're gonna have to wait for it.