Board Thread:Speculation House/@comment-66.116.33.1-20141103215403/@comment-25555436-20150116230716

Or you could Turn The Table. Get into his PoV. He lost his 1st wife/lover. He 2 years later lost his 2nd wife/lover. Shortly after, he almost lost both of his daughters if it wasn't for his Brother-in-Law passing by at that moment.

He already lost 2 of the people closest to him. He wasn't going to lose another one. It's very likely Taiyang overprotected Ruby to hell and back until she went to Signal at the least (and even then, It's likely he had to be convinced to let Ruby become a hunter). He may have also done the same with Yang, but she's more independent, and likely "broke the rules" from time to time.