I can’t speak for anybody but myself, but here’s my take on it.
I rarely ever cooked growing up, it was always someone else either in school or my parents at home. At home my parents made sure to teach me the manners to always say thanks for the food to whoever made it so I have a habit of doing this but I can imagine a lot of people were never “taught” this at home and maybe your guy is one of them.
Also growing up, I was never too worried about my hair since I always kept it short, just like all of my guy friends and the only time we really noticed someone’s hair was if they hadn’t gotten a haircut for a long time and then decided to do so. On the contrary it seemed that the girls I knew put a lot of effort into their hair, changing hair-styles daily and often dying it and I can imagine they also commentated on their friends hair a lot.
If you really feel like this is an issue, tell him that you’d appreciate it if he made more of an effort to notice the things you do (such as when you cook a nice meal for him or change your hair style), but I imagine because of the way he grew up it might not be in his nature to notice these things and express appreciation for it – it does not mean he doesn’t actually appreciate it. Especially in the beginning of a relationship I think you make more of an effort to notice things and express appreciation but as it becomes part of your life for long enough you start taking it for granted.