Why is Turkey not considered an Arabian country?

Some of the reasons why Turkey is not considered an Arab country are:

1) "Turkish" is a nationality itself.

3) "Turkish" is also the language spoken in Turkey.

2) Turkish population in Turkey is around 55-60 million and the population of the whole country is 75 million or so. As you can see, Turks are in majority.

4) Turkish are mostly Muslims but Turkey is the only country whose constitution is not based on Sharīʿah (religious law of Islam) and it's up to citizens to choose their own religion therefore it's much more a free environment.

I hope it was helpful.