The flu vaccine needs ~7-9 months to make from deciding what strains are included to having something in the clinic. This year they delayed the strain selection because of uncertainly. As a result were delayed in getting some versions of the vaccine to the public. Even if the vaccine is not a match getting the vaccine tends to limit the severity of illness. Because there is nothing better, the thought process that something is better than nothing. The data support that notion. There is a massive push in academic science, government and industry to do better.
Remember in the USA ~15-70 thousand people die from flu every year, world wide it is probably ~200-700 thousand. Even limited protection (results in less spread) and a reduction in severe illness would go a long way.