Weeeeeellllllll Not the Daemonic sociopaths and rapists Who were....worse? .... The Primarchs have issues man
A few of the primarchs resented the Emperor. If he had told them the truth who knows how many of them would have gone to the gods willingly seeking aid to defeat Emps.
Less than those who inevitably did during the Heresy, imo. And even then, it'd be a lot easier to tell if they had fallen if knowledge of Chaos had been public. Remember how much treachery the Traitor Legions were capable of because they had the advantage of complete secrecy? Well... they wouldn't have that to nearly the same degree. Things like Istvaan wouldn't have happened, I don't think.
Still can't really blame Big E for being emotionally and even spiritually invested in all he created, especially his sons. He wanted to be the best dad he could be to the entirety of humanity. But in the end he was still human too, and humans make mistakes. Yes he made some mistakes that led to the greatest galactic fuckfest that is 40k, but it's not like he had any ill intentions when he left his sons to make the golden throne. He believed that his sons could handle themselves despite their obvious flaws. His real mistake was not hiring a sitter to look after the kids.
Well it's not like he expected that to happen. However he did know a few of his sons hated him, so witholding the truth about a potential ally was probably for the best, which it wasn't as we all know, but we have the gift of forewarning.
I don't know. Deliberately withholding information of such importance would be grounds for treason IRL. Obama would be impeached, and... probably executed if he did something like that.
IIRC Curze and Sanguinus had that as well, didn't do them much good did it? Emps probably could see the "skeen of fate" like the Eldar did, just a lot messier
It's not logically sound to withhold information that could be Galaxy shattering, I agree But humans don't think logically, they have emotions that cloud their judgement. As ridiculously OP of a human Big E was he still had emotions. He loved his sons, and he did what he though was best. Even if that turned out too...not be the best thing for them at all. Daddy shouldn't have to leave the house and find it dismantled when he comes back from work.
It's not logically sound to tell people that destest you that there are gods who want to kill me and undo all that I have done.