Exactly. It only serves as an important weenie. The entire theme of Buena Vista Street revolves around the intrinsic sights that Walt Disney saw in one amalgamation, the 'adventure' (or, rather, opportunity) he felt, so to speak. All that is reflected in the entrance area. However, just because Carthay is more of a visual attraction than the trolleys, they bear the same meaning behind them.
Now, it isn't the tallest or most embellished structure, of course, but when finished, it will blend in with the surrounding (and currently unplanted) flora. It isn't meant to be the next Cinderella Castle - in other words, the park's symbol - just a visual magnet. The reward of the "denial and reward" environment design.
Now if only the rest of the park was designed with such holistic principles beyond character inclusion within the parks... (sly dig at Cars Land and Bug's Life)