Hi,
Both - the Cananites were evil and, among other bad things, worshipping several gods. If they had been worshipping Jehovah, he would've let the Jews live side-by-side with them.
According to the Watchtower Library, Jehovah repetedly promised Abraham, that his descendants would inherit the country and he commanded Abraham to travel around in the country.
Also according to the Watchtower Library, not all Cananites were killed or subjects to the Jews. The citizens in the cities/towns, which the Jews conquerred, were all killed though.
Jehovah didn't just intend, that the inhabitants were to be removed or driven out. It was also about, that God, "the one who's judging all the earth" (Genesis 18:25) had the right to pronounce a death sentence over those, who deserved it and to see, that the sentence was carried out.
The Cananites were also immoral and sheding blood. Their religion was very depraved. Their "holy poles" were with no doubt fallos symbols and the cult actions on the sacrifice hills were in many cases connected with gross sexual excesses and perversions. Incest, homosexual actions and having sex with animals belonged to "what was common in the land of Cana'an" and it made the country unclean and it therefore had to "vomit its inhabitants". Magic, witchcraft, spiritualism and sacrifices of children also belonged to the abominations, which the Cananites were guilty of.
That was some quotes from the Watchtower Library, which I've tried to translate from Danish into English. Hope, I've managed to translate it into an understandable English.
Agape,
Dane/Ulla