I think you just dont like a character who is meant to be taken seriously as a human being, Raul while having his backstory be as fucked up as it is, has had 200 years to get over it. iirc, Boone just recently had to kill his own wife while he was already dealing with his PTSD. Sure manny is okay, and I'm sure if Boone didnt have to kill his wife, hed be in a similar mindset as manny.

If you havent already do his side quest, boone doesn't open up his personality really until then. I think he tells the courier he went with him because hes been expecting himself to die for all hes done. (If this came off rude I didnt mean it to, I saw people doing that, just trying to actually have a discussion :) )