There's a lot of truth to this, but there's also an aspect about it that's literally just in their own head. Some people just work themselves into a frenzy trying to micro manage their own lives. There are times when I can tell my wife is getting like this, and I will just look at her and say "Hey... chill the fuck out" (With love, she appreciates it, it helps. I know her well enough to talk like that =p)
Sometimes people also start thinking that if they don't do it, it wont' get done, which isn't necessarily true (though absolutely true in some instances I'm sure). I'm a last minute man, and I always will be. I wait until the last minute to do it, but I will absolutely get it done, and get it done well. She's a type A planner and it drives her crazy waiting till the last minute. That's on her. I've never not gotten it done when it needs to be done, but that knowledge isn't going to change someones' personality type. She worries too much, and tries to exert too much control over "life" pretty often.
My wife does most of the foot work in regards to taking care of our son when it comes to shit like washing his clothes, signing him up for health insurance, Dr appointments, etc. But if she wasn't doing them, all of those things would get done by me with zero issue or complaint, just much closer to the deadline than she does it. I'm certain there are times when she feels like if she doesn't wash our son's clothes, it wont' get done. But on the flip side, sure those clothes have been in his hamper for a week.. but he literally has 2 more weeks worth of clean clothes to wear.. so i'm not washing shit until necessary.
She was in Florida for a few weeks to give testimony at a trial earlier this month (Montalvo murder Trial), and our son stayed in PA with me. We had zero issues while she was away and every got done =p. Side note: Both of the bastards in the Montalvo case were found guilty today.
But I'm also an incredibly independent person, and she's pretty independent herself. I have my own personal clothes hamper, I wash and put away my own clothes. I wash my own dishes when I'm finished using them. Bill wise we split the mortgage/rent, and everything else is separate more or less. We pay our own car payments, she pays the cell phone bill, I pay utilities. She buys the groceries, I pay when we go out to eat. We have our own bank accounts and in the 15 years we've been together have never been financially co-dependent on one another.
I feel like I'm rambling/off topic now, but essentially I feel a lot of the time the "Mental load" isn't nearly as large or heavy as people make it out to be. There is absolutely an aspect of them building it up to something it's not in their own head. At least in regards to my wife. She tends to agree with me, but again it's a personality trait that doesn't just go away.