I think it's a bit simplistic to say "they're just thick" - as tempting as it may be. But I have seen first hand that the group of women I'd consider markedly "unfeminist" or apathetic to feminism tend to be, ahem, shall we say, intellectually not very curious...?
Either because they genuinely don't care (e.g. never seen first hand the effects of anti-feminist practices or felt like they've been a victim or discriminated against personally) or because they just don't want to acknowledge the merit of what feminism has done in the past?
Take my MIL, for example - she's in the second camp - a SHAM to her children whether she wanted to or not (there was never much choice, in that FIL is extremely traditional and doesn't agree with "women being bad mothers by working full-time blah blah blah"). Despite the financial realities of the modern world meaning that their viewpoint about raising children is literally impossible for millions of hard-working mums and dads (that dad = earns enough to support an entire family, mum = stays at home forever), she genuinely believes that "women shouldn't work, especially if they have young children".
This is a woman whose husband hasn't paid into a pension for her, and doesn't have NI contributions in her name. Quite literally, when FIL pops his cloggs, she is going to be financially fucked, as well as practically (she can't drive, has no idea how their bank account works).
To acknowledge that her viewpoint is flawed (and anyway, not financially viable these days, as mentioned above) she will not participate in a reasonable discussion about it.
I've tried. An example was last week.
Whilst watching reality TV, a young mum was trying to get a home build finished before she went back to work from maternity leave. MIL commented "that's just wrong, how can she think about going back to work with a little one just a year old" (the dad worked too).
I was 
and said "perhaps they need her income for the mortgage" and left it at that, and I just got "the look" - the one that means "gaaagh is being a trouble-maker again".
MIL has absolutely no intention of verbally agreeing that there is any "right" way than "her" way - to acknowledge anything other than her reality would make her open to recognising the weaknesses of the position she finds herself in. No pension, a scary retirement if FIL dies before her - she cannot acknowledge there's been a flaw in the set up she's been defending for 30 years. To do so would be too scary a prospect.
Hence, it's easier to go with the whole cognitive dissonance thing and pretend it'll all be fine. Typical "bury the head in the sand" stuff.
And that's why she continues to be the most staunchly anti-feminist woman I know - because it exposes the very problems that she faces in her own life, and I suspect she considers any feminist thought on certain life choices to be an attack on her life choices. It's too close to home for her to verbalise thoughts in any other way than the way she does (feminism = bad, the past = good).