Given that the diagnosis and condition are so wide, I'm not sure how anybody can suggest children of people with autism aren't impacted.
My children have to understand why their other parent does not react when they call out for them. They have to - age 5 and 7 - understand that this person who loves and takes care of them literally ignores them at key times when they need them. I have to explain that sometimes OH gets tired and shuts the world out to take a break and isn't ignoring as much as can't hear them. For the kids, they are certain it's because OH doesn't care as much about them. This happens at least weekly. They can be standing right beside OH calling out and get no reaction.
If you know what it's like to be ignored by friends at school - sent to Coventry - then you can imagine that this can be damaging when it's repeatedly done by a parent.
Also difficult for them to understand why when they cry, unless there's an obviously (like blood) physical reason for being upset, why OH has zero sympathy. They're simply not allowed to be upset unless OH sees a reason for it.
This is how OH's autism impacts the kids in a negative way. They have to adapt to their parent in a way that's cognitively and emotionally too difficult for them to understand. I do what I can to smooth the waters - on both sides, because OH gets angry at them being upset "for no reason" and doesn't let it drop.
Is OH bad person? Absolutely, definitely not. Their autism impacts their ability to read others and deal with any types of emotions in others - including happiness (gets stressed if kids are too happy too). And it impacts their ability to believe something if they can't see it or haven't personally experienced it. They're also not willing to apologise for upsetting someone if they don't think they did anything wrong..which obviously causes a problem if they can't see anybody has reason to be upset. Not everybody with autism is the same, as we know, but these are the parts of OH's diagnosis that are prominent for them.
The kids aren't carers - OH is amazing at looking after them in many other ways (I say amazing as they totally outstrip me!) - but they definitely are faced with not only a lack of emotional support from one parent, but an absolute negation of their feelings. As kids are full of emotions that they need to learn healthy ways to deal with, being told they have no right to feel them, IS hugely and negatively impacting them. As they often learn these ways by watching their parents, it's very difficult at this age for them to understand what's going on. The kids are basically expected to fill in the emotional gaps left by OH and not feel emotional pain when they do. Even if I can help them understand that their other parent has a different way of looking at things and seeing things, it doesn't remove the painful feeling of having emotions ignored or completely dismissed, their experience denied.
Clearly not everybody with autism is the same. But some people do have manifestations of it that can make intimate interactions with them very difficult and damaging for their children.
NT people can also cause problems for their kids, but that's a whole other thread (and there are many on Mumsnet about the damage "NT" people can do). This is specifically about autism and my OH's autism definitely is causing significant problems for the kids.