My idea of strict trainnig is trainng done with a purpose. So instead of just riding hard one day then the next say "today ill go easy" its more laid out so that you work on areas where you are weak while at the same time maintaining your strong areas. At the end of every cycling (4-8 weeks) re-eval yourself and see what adjustments you need to make.
I agree everybody will improve if they just get out and ride but feel everybody would improve at a faster rate with some degree of structured training. Just dont think that what the OP has is a reall over the top "strict" training plan. Always good to have some sort of focus exp during the winter months.