MGTOW is basically not letting America, a matriarchal society, Define what your worth, role, and responsibility is as a man.
For example:
Man approaches woman, Sparks interest, sets up date, makes her his girlfriend, continues to pay for dates, marries woman, impregnates woman, and takes care of her and her kids until he dies.
You may not be fully mgtow, but if you believe that there's anything wrong with any of what I listed, you are at least partly Mgtow.
There are a lot of men who Define their worth by their ability to do at least one of these things. Mgtow is about finding worth in yourself as opposed to finding your worth in what you can do for a woman, which is how much of America defines manhood.
Incels and the alt-right have pretty much invaded the movement though, and have altered what it means to be mgtow altogether