In Macbeth's time, there was a lot more expected out of men than today, because they thought women were not capable of these responsibilities. Men were expected to be ruthless warriors. They were not allowed to be sensitive or show emotion. Being a man meant having to fight and kill and show no signs of weakness.
Today, men are seen differently. They carry less responsibilities and it is okay for a man sensitive. A lot of men are portrayed as kind and successful. I don't think modern media's representation of men is entirely true. Men are portrayed as predators, of people women need to be afraid of, which is not true for all men. There are also instances where feminists go to the extreme and label women as better than men, but feminists are supposed to be fighting for equality, not superiority. While I think our perspectives has dramatically improved over time, they are not perfect, but society is constantly changing it's views and i'm intrigued to see what the future brings for men.
I think that being "manly" means being proud of who you are, fighting for what you believe in, and treating everyone with kindness.