Cairo is a city that, in recent years has experienced a drought in tourism. Cairo does remember however, what it was like in the boom times. This leads not only to desperate vendors, but desperate AND pushy AND relentless. But it's not all bad. To me, a 26 year old man, it is a VERY safe place. I can walk around without fear of getting mugged. Getting mugged off though is a different story. No one is your friend but everyone insists that they are.
Insider Tip:If someone invites you to their shop/house/dwelling for their "Egyptian hospitality" this means they want to get you to buy something. One guy invited me back to his shop for some tea. It was my first night there so I fell for it. He tried to get me to buy his papyrus. I said no thankyou and he said "Look only". I offered him money for the tea and he said "It's free, it's my Egyptian hospitality". Subtext: buy my stuff then I make a profit on that tea. Just firmly say no and leave/avoid the whole situation.