Yes and I also think there is a tendency to expect better behaviour from a woman than a man and I can't agree with that. Women are perfectly capable of behaving very badly, just like men - and we should expect no more, or less, from one sex than the other. Having been there myself too, what does it say about the men's judgement and values at the time, that they chose such apparently ghastly people with whom to get involved? One of the essential parts of affair recovery is for the involved spouse to reflect on his own judgement of people and situations.
I am very firmly in the camp that OW/OM share the blame in these situations, but they certainly shouldn't be blamed more than the spouse, or the spouse infantilised as being somehow powerless to resist the attentions of a predatory and morally bankrupt man or woman. The most powerful lesson a predator will learn after all, is if the targets of their attentions vilified them for hitting on an attached person and sent them packing in the first place. Predators are only invested with power if an involved spouse accepts their entreaties, after all.
It's expecting far too much of a betrayed spouse to empathise or even feel neutral to an OW/OM, because their intrusion in a family stirs up primeval feelings of being invaded and attacked and the anger is huge. But eventually and it does take some time, that hatred does have to be unpicked bit by bit (especially the sexual politics) and the anger, directed at the person most deserving of it - the faithless spouse.
I entirely agree with spidookly that it is really shitty behaviour if an OW/OM exploits a marriage that is going through a vulnerable time, either because of one of the partnership's personal life crisis or because there are marital difficulties. That's exceptionally low, vulture-like personal behaviour and exploitative of the reality that temptation can be especially hard to resist if someone is going through a crisis. A true "friend" to that person wouldn't add to the crisis by offering an affair, that is ultimately going to deliver a death blow to a faltering marriage or bring even more misery and confusion to a person whose marriage is basically good, but is being damaged by depression or mid-life reckonings. Many people in the latter camp will agree to an affair as a form of self-medication; to escape for a while from their own personal demons. It's just about the worst prescription there is, however and OW/OM know that too.
Going forward, I do think it helps to stop thinking of the OW in one-dimensional terms and to stop vilifying her. What tends to bring more healing is if you try to get inside her head and wonder why she chose to play this role. There are as many different motives for being an OW as there are for affairs and whilst I think the hackneyed stereotype of a low-esteemed woman who is always treated badly by men is old hat now and there are plenty of OW engaging in "guilt-free" affairs, I still think it helps to question why that is and try to understand it. Her behaviour was a choice she made - why is the question? Hard as it is, it is actually more healing to you if you humanise the OW and try to understand what makes her tick. Once you bring her into the light, her power recedes. Once you understand her bad choices, you can develop empathy in some cases and pity/contempt in others
Once you conclude that the OW herself made some very bad life choices and ones that will never make a person happy, it is easier to divest her of any power she has over you. You might perhaps hope that she gets some therapy or some help to get her to review her own behaviour and take responsibility for it. You might conclude that if she continues with her train-wreck of a life, she will never be happy and will therefore become the ultimate loser in life.
But you can only control your own life choices and if you're someone who likes women, values female friendship and doesn't expect higher standards of behaviour from women than you expect from men, you will be living your life well and with dignity.