I normally love Lego's interpretation of various real architectural works but I don't believe there is enough detail here to really capture the unique style of Gaudi's design.
Could they make a bigger version of this set that is more closely resembling the real thing? More than likely, yeah they can; look at the displays they have at Legoland. But would that more detailed version be accessible for even the well off AFOL? Most likely not. It'd be too big, too expensive, and too unwieldy, and will probably still fail to capture some of the details of the real thing.