Yes and No. That's the only true answer.

A lens has to be adapted to your vision and subject. Landscape is a very broad category and I know fine-art landscape photographers who mainly shoot with wide lenses and others mainly with telephoto lenses (ex: 70-200mm).

The angle-of-view of ultra-wide lenses really emphasizes the foreground. Moving back with a longer lens is not equivalent (as someone suggested) as it changes the relationship between of things at different depths.

In some locations you end up very close to the scenic vistas (beaches, nature trails) and there are interesting foreground details which deserve emphasis (flowers, seashells, moss, etc) in which case a wide-angle be easier to compose with. Other locations, the interesting things are far and without a long lens is becomes difficult to make an interesting shot.

Regardless of what angle-of-view your lens is, you have to be able to fill the frame with interesting things. Jay Maisel says 'Everything in your frame helps you or hurts you'. If I can crop an image without changing the aspect ratio of my frame, I consider that I failed to take the best shot possible.

Take the shots from you gallery for example and imagine if there was more to the sides and above or below. Would the shot be more interesting? Or would people start wondering what its about?

SUBJECTIVE PART NOW :)

Honestly, I consider myself a wide-angle shooter, most of my photos are taken wide but I also know that it is much harder to make a wide shot work. That does not mean, I should just shoot with a longer lens because what I see in a scene is how things combine and contrast, some people see details more and that is simply a different way of seeing.