Is it normal that my family members ignore my brother's issues?

My half-brother has some significant mental issues, but anytime someone brings this up, the rest of the family ignores them and continues to tell him that the things he does are anyone's fault but his own. He was married to a woman for less than a year and up until and during that time, he grew jealous of the Best Man because he stood too close to her, was jealous of the fact that her father held her hand down the aisle, did not permit her to have a job, go to the gym or have friends, used other people's money to go to school but kept flunking (and didn't pay anyone back), scared his wife because he had a shitty temper, and got a restraining order against her father because he had to come over to fix things and this made my brother feel inferior. When she got scared enough to leave, he threatened suicide and refused to allow her to divorce him, saying that she was his property and that Biblical law does not allow her to divorce him. He then went to her father's house in the night, broke in through the window, and had sex with her one more time. Though he continued to see other women during the divorce process (even apparently having sex in our yard while we were away, according to a neighbor), he continued to claim that his then-wife was "[his], and shouldn't be able to see other people or leave [him]" during or after the divorce process. His ex-wife has a restraining order against him, and he still blathers on about shit he should have gotten over already (at one point, I was concerned that he might be stalking her). Whenever anyone points out that he has problems, he claims that everyone is 'attacking' him, and he blows up or just crawls away like a little insect and sulks for days on end. Despite all of this, my family members continue to tell him that nothing is his fault and anytime I suggest that he get counseling, they ignore me. Our family knows everything he's done, and yet, they still tell him it's not his fault and say that nothing's wrong with him. Is this normal?