Visitor Q, on 21 Aug 2014 - 10:28 AM, said:

I've always suspected that the Emperor planned to get rid of all but a few of the Primarchs and the marines after the Great Crusade and isolating them both emotionally and phyisically would have been a perfect foundation to do this.

It would also be an interesting explanation for why he made sure that Marine geneseed only works on men - it's an elegant way to prevent unchecked "breeding". After all, to the Emperor, the Space Marines were nothing but tools; he did not want to replace Mankind with them (which might otherwise have happened, given their genetic superiority), but merely have them be the vessel by which Mankind conquers the stars.

In Horus Heresy Book (I know you love them, Lynata! ), it was spoken in a few places that the Emperor created the Thunder Warrior or a purpose and then disposed of them, and it was said that it was sure that the Emperor had the same kind of plan for when the Space Marines would have done their part.

(please keep in mind that all the space marine venerate the Emperor, the god that descend on heart to save humanity, he create the primarch and the chapater, for defending humanity. He die for defending the imperium of man.)

A lot of Space Marine chapters doesn't worship the Emperor as a god, nor even worship Him.

and it was said that it was sure that the Emperor had the same kind of plan for when the Space Marines would have done their part.

Yeah, that's a rather popular theory elsewhere, too.

Maybe if the Emperor came back, he'd look at the geneseed corruption of Space Marines in M41 and be like: "No wonder it's so bad, they're all past expiry date!"

The Emperor would think many bad things about his Imperium if he came back.

Here is the irrefutable proof!

https://www.youtube.com/show/theborealecast

and it was said that it was sure that the Emperor had the same kind of plan for when the Space Marines would have done their part.

Yeah, that's a rather popular theory elsewhere, too.

Maybe if the Emperor came back, he'd look at the geneseed corruption of Space Marines in M41 and be like: "No wonder it's so bad, they're all past expiry date!"

He did pull that stunt on the Thunder warriors. What a do*che!

The big E: "Sorry guys, you're obsolete! I need something better for my conquest of the galaxy. I shall forge legions of star warriors and twenty supermen to lead them into battle! They shall be as gods unto men and... yes, Malacador ?"

Malcador: "Forgive me sire, but if I may: One : You wanted a secular galaxy so setting up your sons as demi-gods won't do."

Emperor: "But-"

Malcador: " Second : You really should make them female sire, Boys will be boys and there wiil be rivalries."

Emperor: " Malcador! I won't be a father to a bunch of-"

Malcador: " Third : Will the space marines be made redundant to? What if we have later uses for them?"

Emperor: "Ooh space marines, I like the sou-"

Malcador: " Fourth : I just don't think it's wise to create warriors with a built in expiration date."

Emperor: "Now look! You can't expect me to keep all this old junk ly-"

Malcador: " And Fifth , May I remind you we've only just begun the unification wars and you telling the troops they are utterly expendable assets that are engineered to expire and die within a few years, to be replaced with something better, really isn't doing their morale any good. Actually some of them look quite angry ."

Emperor:" Ah yes. That was a slight oversight of mine. No matter, I'll fix it!"

Malcador: "No wai-"

Emperor: "+++ All of you! Forget this conversation happened at all! +++"

Emperor: "There, that's better, eh Mal?"

Malcador: "What's better?"

Emperor: "Sigh."

A bit of ambiguity is a wonderful thing in 40k storytelling. Not every mystery needs to be explained.

But wild guessing is fun!

As for the OP...

Unless an astartes has gone renegade, and not even necessarily then, they aren't going to slaughter humans for no reason. Even the Marines Malevolent have reasons for their actions, even if they boil down to cold-hearted expediency.

My current character is from the Steel Angels, a custom chapter that are very proud of their heritage as sons of Dorn, and have huge respect for other astartes as sons of Dorn and other primarches. But humans are at best marginally competent and at worst, traitors waiting to happen. Their only real advantages being numbers and ease of replacement.

They rule their own homeworld directly, and battle-brothers often lead squads of PDF as part of their training. This generally leaves the battle-brothers with a very clear idea of the relative weakness in mind and body even the supposedly "better" humans regularly display. In this case, familarity breeds contempt.

Regardless, the Steel Angels will fight tooth and nail to protect humans. To uphold their duty and their martial honour. My own character isn't a particularly extreme case, he's pretty dismissive of humans but bears them no malice.

My view of it is that most Marines do not care much for humans either way but tend to expect them to fail more often than not. A rare few Chapters might promote the idea of humans as being worthy and their lives having some special importance while on the extreme opposite side there would be Chapters who do not care much for humans at all but expect them to breed like flies and replace any losses they might suffer during the Marines' operations. But then again I personally don't think that we should discount the possibility of personal views on the issue, at least if the games Dawn of War, are something to go on. In there you'll have both Avitus who don't give a crap about humans and Thaddeus who is very passonate about defending them, all in the same Chapter. For my personal belief I'm wondering if not Chapters have held different views of humans at different times throught their often long histories.