Has Impressionism become a mannerism?

Browsing the gallery I notice that a lot of paintings, especially landscapes, are done in a loose style that follows the general principles of Impressionism, that is alla prima loose paintwork, visible brush strokes and lost and found edges, and I wondered if this is now a natural way to paint for the amateur or semi professional artist. It also seems to be the accepted way of painting in The Artist magazine, so many articles are devoted to the idea of loosening up or freeing up your paintwork, that I would suggest that this has now become an unquestioned convention. With the Manet show upon us it is tempting to think that perhaps a lot of artists tend to know their Impressionist art history and very little that came before or after. There is also an identifiable strand of "New English Art Club" style of Post Impressionism among professionals who are featured in The Artist, that is also perpetuated by the Mall Galleries. It is interesting that a movement that was once seen as radical has become the conventional way to paint and is still with us, so are we all still Impressionists? P.S. before anyone gets upset, I mean amateur in its proper sense, that is painting for pleasure. It is not meant as a derogatory term.