I would because I believe in the mission of connecting the world. The scope and nature of the task makes it immensely complex. Moreover, to keep the service free, some amount of ad monetization is probably necessary too.
I am aware that the company is not without sins. I would like to help solve those issues internally rather than exclude myself from joining the company.
Ethically, not joining Facebook is an act of omission and doesn’t ensure the person who will join in my seat will do a better job. If I truly think what they are doing is bad (i.e. more bad than all other things in my considerations), the ethical options are either to build a counter facebook or to sanitize it.
