It's a joint decision. If our marriage broke down and DH turned round and called me "lazy" for not working more, he'd get an earful.
But, in all fairness, this is exactly how it happens... the joint decision which works really well for both parties (man enabled to earn well, woman happy with lower paid flexible job and spending more time with DC)... and then shafts the mother when the marriage breaks down.
I'm honestly not trying to rip your situation apart because it obviously works well for you and your family... but you've said in one post:
I've always had an issue though with men (and it is mostly men) who are happy to take advantage of their partner's unpaid labour and leave all the chores and childcare to them while they build their careers.
And then gone on to describe your set up as exactly that ^^
It works well but it's so precarious.
So you earn 1/10th of DH's salary... if I was you, I'd be pushing for HIM to take the step back from his career while you do everything possible to get your salary up to a level where you could theoretically support yourself if you had to (maybe you're already doing this, in which case fair play!). If that means putting DS in a nursery and making him foot the bill with his vastly higher salary then that's exactly what you need to be doing.
Then, when the marriage breaks down, the spouse is 'lazy" and should shut up and get a job.
Well yes, that is exactly what happens. And it just so happens that it's usually the mother because it was the mother who was happy to enable the high-earning DH when it suited her and she was benefiting from the arrangement.
It's not as if people don't understand the way the game works these days. People should know the rewards of enabling the high salary don't come without risks to the sahp / lower earner.
The low earner / sahp (wether that's the mother or the father) will have to get a job to support themselves in the event of a split. It doesn't really matter how much of earful the one who needs to get a job gives the higher earner... that's just the way the world works. No amount of earful will stop that person needing to support themselves.
The lower earner (and it is usually the woman) needs to accept that when they agree to these join decisions.