Why are people justifying dany brother viserys 3

So viserys 3 is a kind of person who married off his sister to a brute like drogon . To get a army to get. His throne back . And when dany is pregnant viserys storms in and threatens to kill her unborn baby if drogon does not give him a army . Viserys deserved to die the way he did . But still 2 years ago i came across posts that justify viserys saying that raising a little sister and living in hiding is too hard . I really don't understand why people defend a psychopath like viserys 3 ..