Not really. Some people, myself included, argued that whilst we didn't strengthen sufficiently, we also didn't lose any of our important players, so it wasn't all bad. In hindsight not getting in a centre back knowing how unrealiable Steven Taylor is, and hence having to rely on Williamson as much as we do has hurt us the most. Other than that I don't think you can attribute our poor season to the transfer window failures too much. Poor player form, Europe and injuries/suspensions have all contributed far more than our ultimate failure to bring in someone like Debuchy if you ask me.