Serious Writing ?
Writing, I have always thought, is done seriously unless someone is playing the fool. Just to impress an impressionable teenager or to show off to the soft-hearted teacher- and they will smile anyway.
Writing even a piece of office memo is at times, a poetic effort on part of those, who have a flair for writing or for expressing themselves clearly, in a civilised manner, with a degree of articulation.
Much writing one can see in political propaganda and commercial jargon filled leaflets, has a serious intent -but the style may leave much to be desired. They do not care, those who are in a souped up evangelistic hurry to get it over with.
Writing, if done as a 'content' for a portal, as some of us who do technical writing, can also be sharp enough though forcibly squeezed out of the writer, and that does not slacken its tautness nor its stolidity nor its relevance either.
Writing, if the writer has the writing skill, could be seriously useful to many readers, even when frivolous -this may sound like a contrived oxymoron, but that does happen.
Writing when not serious, can be playful, interesting and piercing -provided the writer has the knack to juxtapose the right words and phrases even when not serious.
In the end it is the reader who decides whether a piece of writing is serious, or non-serious or downright phoney : writers will seldom agree what on earth is writing or serious writing or pure baloney.