fair - I don't know if any system is fair. That said, it looks like you got lucky and had a curator give you a vote. Often, curators have a whole trails of votes following them.

This is good for the person who gets the vote - but also for the person voting. by voting, you earn curation rewards. Granted, they are much less than author rewards, but still, it is something. If you let your 100% voting power just sit there, it doesn't do anyone any good.
Many people want this platform to succeed and want people who post quality content to stay. So, they actively look for good posts and give them attention. Obviously, that takes a lot of time and not everyone can do this. But many want to support those authors as well. So, they join a curation trail. A finds the content, votes on it and B_Z automatically also cast a vote - often a very small percentage, but en mass, it adds up.
they earn curation rewards without having to worry about it, the person voted on gets a better payout and hopefully, everyone is happy in the end.
Hope that makes sense...