The possible personality of Vegeta's mother
Personally, I believe King Vegeta chose the strongest female Saiyan, regardless of her personality. This raises the possibility that Vegeta's mother had a personality very similar to Tarble's—kind-hearted and perhaps protective.
It is quite likely that King Vegeta kept Vegeta away from his mother to ensure he turned out just like him. Furthermore, this would also explain why Vegeta never spoke about his mother.
This is just a theory, in case we ever get to see something of Vegeta's past and how those memories put him in conflict with his doctrine.