It's indisputable that men and women are different in many ways. Are women inferior? No. But certainly different. That means that women naturally have different roles to men. As the saying goes, "A woman wasn't supposed to do everything a man can do, but everything he can't." Our roles are complimentary.
Thanks to real feminist movements, women don't have any real problems in the West. Feminism has done its job, so now we're only trying to maintain equality. But with traditional Feminism having been victorious, a more radical version has taken its place. It is not enough to some people that women be equal, they have to be the same. If you suggest that men tend to be better at one thing, or women tend to be better at another, that's "sexist", which is why it makes perfect sense to let a man compete in women's boxing matches and let him beat them to a pulp. Yaaaaaaaay!
Unfortunately, this view has even infiltrated the Church, so many Christians believe it is wrong to say that women can't be pastors. The Bible has a few things to say to such people, but it is not the primary purpose of this particular article address believers. There are, however, many unbelievers who look at the Church and say the fact that only men can hold certain Church roles is sexist. My question to those people is why do you care?
If you are not a Christian, what possible motive can you have for wanting to be a pastor? You don't see me barging into a mosque and demanding they let me become an imam. If you don't believe a religion, there's absolutely no reason to care who plays what role within it.
Furthermore, the Church belongs to God. If God owns the Church, He gets to set the rules. The Church has the authority to enforce these rules within the Church. Therefore, God has the right to say "only men can be pastors", the Church has the right to say "we will not let women become pastors", and whether you believe in God or not, there is no legitimate reason to be offended at the idea that women cannot be pastors. If you're a believer, you shouldn't be offended by God's rules because they are God's rules. If you're an unbeliever, you shouldn't be offended by God's rules because you don't think you need to obey them anyway. The fact that this is even an issue for non-believers reveals that it's not about unbelief. It's about pure hatred for a God they claim does not exist.