"Home" can be used as a countable noun, as an uncountable noun, or, as you so astutely point out, as an adverbial particle. Why? The short answer, it just is -- that's English. It's the same in the other Germanic languages. "To go home" is a phrasal verb that uses a noun rather than a preposition as the adverbial particle. Good job noticing that, Wind!

'Home' can be a noun or an adverb. If you want to use it as a noun in this sentence, you could say something like 'go to my home' or 'go to his home.' When it is an adverb, it describes a direction instead of a 'thing.' It is like saying: 'Go left' or 'Go forward' or 'Go back.' 'Go home' means to go in the direction of home. I hope that helps!

Home is a countable noun: how many homes do you have? I have one home. It is also an adjective: my mums home cooking is the best! Which team is the home team? And also an adverb (in the direction of home, towards home): I'm going home for lunch. Can I bring friends home after school?