Why am I not allowed to dodge in kendo?
When the opponent strikes at your head why am I not allowed to sway back to dodge it and then counter attack?
If we talk about what is allowed and what is not, you can doge to avoid cuts on your head. BUT
it is not seen as an appropriate way of defending yourself.
Dodging may be useful if we just concentrate on hitting or being hit. But Kendo is not about hitting or being hit. Kendo is to learn our weaknesses. So if you fight and get hit, learn your weakness from it. And analyse how your mind was working before you got hit.
And also it is often said that if you have time to dodge, you should strike. If you have time to block, attack.
If you know that your opponent is coming, try to strike instead of dodging. Since you do not really have to learn how to dodge, try to do what you are not good at. It is very useful to improve your skills if you think in that way. :)