Your friends and family cannot see "your" collections on their Adobe accounts because your images are on your account, and not theirs. That is why it is necessary for you to send them a link. Even though the link is public, the only way anyone is going to see those images is if they have the exact link to access that collection. It isn't as though Adobe is providing a massive open link to allow everyone you choose to connect to your images. That simply isn't how it works.