Al Wahab is a name of Allah but this is not why Wahabis are labelled as Wahabis. It is because they follow the teachings of a certain Abdul Wahab who along with Abdul Saud with British support and guidance laid the foundation of the Kingdom of Saudia Arabia.
I know why we're labeled as "wahabis" but I'm telling you that it is incorrect as 'al-Wahab" is one of the names of Allah Ta'ala. You're distorting the name of Allah Ta'ala. Secondly we don't follow Shaykh Muhammad ibn Abdul Wahab (rahimahullah). We simply respect and love him as like we do for scholars who came before and after him. Let's suppose we do follow him, please tell me what did he say which was not said by the scholars who came before him? Let's just focus on the matters of tawheed and 'aqeedah.
As far concerning how Saudia Arabia came to be and this old myth of him being aided by British, you need to read some history from neutral sources.
It is true that when the heretics can't justify their shirki beliefs from the Qur'aan and Sunnah, then they start spreading hatred and falsehood against the noble scholars of Ahlus Sunnah.