You would think so. But I don't think it was that bad. Most combat was at range, and the most common close quarter combat was some type of polearm. Helmet was also tied and secured.

But probably most importantly, those ornamental head figures are really restricted to high rank commanders, often large daimyos. Lesser samurai or lesser soldiers had little to no ornamental heads. In other words, the men most likely to fight did not have such elaborate decorations. The men who mostly did not need to personally fight but needed to be seen and heard did have these decorations.

The outlandish shape of this kabuto would tend to suggest to the uninitiated student of Japanese armor, that it was made for predominantly decorative purposes. In fact, a large number of helmets made during the late Sengoku period…were in fact kawari kabuto – many of which were often far more bizarre than this particular example…
There were a reflection of the warrior’s desire to be recognized, with on the crowded battle fields of the mid-sixteenth century was no easy task. Although vanity was a strong factor behind such designs, they could also serve a necessary function in allowing important figures to make themselves easily identifiable to friends and foe alike. There were also a psychological advantage to be gained by many designs of kawari kabuto, which make a warrior appear taller and more menacing.