Sorry in advance if anyone thought this was gonna be a chapter but don't worry I'm gonna release the next chapter tomorrow along with the latest Patreon Chapter.
Ok back to topic, I've seen that a lot of people have conflicting views and questions regarding the Emperor of Mankind or as we call him, Big E.
First of all let me be very clear, as someone who read the books I noticed that the narrators for these stories is very unreliable and biased, which is normal since it's accounts by different people of different factions.
A imperial was gonna glaze the Imperium while a Chaos narrator was gonna be horny for Chaos and extremity.
And Big E was not exempt from this so as a veteran of the books and lore who also knew about some of the retcons done let me give you a non bias view on Big E.
The Emperor has been around ever since the Bronze age and was born both as a powerful Psyker and a perpetual and lets just say any guy or girl would become god like when you had that type of load out and tens of millennia of time to practice your gifts.
Big E loved humanity BUT he was a introvert and preferred humans to live and thrive their own way without any involvement from him, every time he intervened in history it was in disguise.
He was literally Alexander the Great and Siant George in fact a lot of mythical gods were inspired by him like the Norse God Tyr.
And he was happy with his approach.
At this time the Emperor while seeming a bit distant at first glance was very reasonable, calm and empathic nor did he suppress his emotions, there's also a chance he was one of the Men of Gold or even the first one.
But then the Age of Strife happened, he was stranded on Terra and couldn't do much as for several millennia his race was brought to the brink time and time again.
Seeing the damage done and the possible futures he saw through his precognition Big E finally accepted to reveal himself after Malcador's urging.
Now the problem was that Big E couldn't go through things slowly since this was also a ripe time for his biggest enemies Chaos to burrow themselves far deeper in the material universe than they ever had especially since there was now 4 Chaos Gods except 3.
So Big E had to go with the monarch route, he would unite Terra and then all of humanity under his banner by any or at least most means necessary and after he was done with his Webway project he would focus on consolidating humanity's power and removing undesirable elements like corrupt and greedy humans.
To do this Big E had to suppress his emotions so he could go through the necessary actions and this was important because contrary to popular belief, Big E had LOTS of Love and Hope.
Which wasn't that weird since if he was the embodiment of human potential that also includes the good sides of humanity.
But in these situations they would have been more of a liability so he suppressed them or that's what he believed.
Now you gotta admit if you take a introvert who didn't like leadership and rarely even showed himself and had him suppress his emotions so he would be more logical in his actions a lot of Big E's actions could be explained.
As for him being a bad father? Come one man, you expect a guy in these circumstances having the capacity to be a normal functioning parent!?
On top of him having a interdimensional project to complete, an empire to lead and keeping eye on four very dangerous Warp tumors.
But the key word here was "suppressed" meaning the Emperor's emotions would rise to the surface, he genuinely loved Horus like a father and not just him but other of his sons too.
It's just that he was even before all this mess not used to expressing himself openly (Courtesy of being immortal) and until everyone was safe he couldn't since everyone had a part to play and that included himself.
But aside from his orders Big E was also very off hand with how his orders were carried out, he pretty much gave the Primarchs free reign on how they wanted to lead their legion and armies in the Great Crusade and only intervened when one too many lines were crossed like with the World eaters and the Night lords.
As long as they were brought into the fold and paid the Tithe on time, and speaking of Tithe, even that was different in that era, since the Tithe was designed for every category of world to make sure even if there was problems with timing due to Warp travel the worlds would still be able to pay it.
Even the Xenophobia was a means to an end not that he wasn't justified in it, since most of humanity's "allies" backstabbed them when the Warp storms hit either due to greed or due to circumstance (No the circumstance ones don't get a free pass since instead of using diplomacy they also decided to attack humans first of all).
So Big E would give his armies a legitimate target and also make an example to the galaxy that while humans were very lenient and kind (In the DAOT they didn't fight against Xenos instead signed Non-violence pacts with them.) they weren't a race that could be taken advantage off without consequences.
And this was how Big E's mindset was in the Great Crusade Era, at his core he was a pragmatic and logical leader and almost all his actions had a legitimate reason behind them even if they were ambiguous.
Remember that Big E had MANY supporters that fully believed in him and his dream and many of them wanted to see that vision become a reality and this was not only due to his aura (It helped but not fully.)
Even his most skeptical supporters if they got to know him a bit and saw his motivations would become. "He's out of line but he's right!"