I think a lot of younger women/people feel that it's not right to live 'off a man' and they worry about the risk of being financially dependent on a man.
Obviously your DH is happy to finance you and you trust him. Also he will gain a lot from the extra time you'll have to sort things and make both your lives less pressured.
I sometimes wonder if the pressure of both parents working sometimes creates stress and puts a strain on the relationship.
There must be a massive difference between working part-time and working full time.
On the other hand some SAHMs manage to make a full-time job out of helping on PTAs etc!
I think if you feel that you'd enjoy being a SAHM and your DH is happy too you're lucky. No commuting, office-politics, having to wear work clothes, worrying about childcare, worrying about taking time off when the DC are poorly, feeling guilty about missing their important events, taking time off to go to parent's appointments .....
You will save money and probably be more environmentally friendly by being a SAHM - more time for shopping around, more time to make do and mend, more time to cook from scratch, hang out the washing instead of tumble-drying.
You would have much more freedom - if the weather's nice you can be outside enjoying it, you can organise your time the way that suits you.
Recently I went to a short course on parenting teenagers, expecting to feel bad about my parental shortcomings. However I was struck by the number of parents saying how difficult it is to find the time to listen to their DC/ have a meal round the table/have quality family time.
It annoys me that so many working mums appear to look down on SAHMs. Especially as I am free to look after their DC when they need a hand/take them back to my home when the school phones their parents to say they're poorly/have them here when the school is unexpectedly closed due to bad weather/strikes etc.
I still remember during my first job pre-DC how an older and quite senior colleague always seemed to be rushing off to attend to some children's crisis. I blush at how unsympathetic I was, but she was always complaining about how busy she was while being very well-off. I had to bite my tongue to provide her with the obvious solution to her problems...... She was keeping someone else who probably needed the income out of a job too.