Many of us have decided this - check out the growing single motherhood by choice community.
I love men - really - but have never wanted to be tied to one forever. The one time I lived with a boyfriend, I absolutely hated it.
I like sleeping alone - I sleep better. And I like waking up alone, and having luxurious, thoughtful mornings without anyone else breathing down my neck.
I'll spend time with men in the evening, but only if I feel like it.
I do worry I might get lonely as I get older, but I've always found relationships with other women (non-sexual) to be more nurturing and satisfying than those with men.
And, as your experiences shows, a lot of men disappear when the going gets hard (I know of a man who left his wife when she got cancer, and this was after she'd nursed him through his cancer, and then he married another woman, and left her when she got cancer, then he died of cancer while tended by his third wife), and men mostly die first, leaving their wives alone anyway.
I don't look down on women who decide to get married, but I know it's not for me.