I have had a same issue, people are not trying, most people are getting designs from the Internet, and most of them are not even professional designers, it looks like they are just playing around with photoshop and thought to try their luck to win some cash by entering design contest. I don't blame the author. And no there is no binded contract in a contest. Why should one waste there money on a logo which they don't like or will never use? For what we know that Logo can be a copied template logo! Honesty where are the professional designers that I used to see before, there were only 3 of them and the rest used to be use trying out photoshop. I've just had a bad experience, and I'm going to go fiverr to get a design. I'm not even the author and I've had a look at all the designs and out of all of them only found 1 to be 'ok' and all other ones are a joke. Like 1 person has designed 6 logo all in one go, clearly the word quality does not exist. And one person has just typed it in different fonts, I could have done that in word.
There's an implicit contract. There's a choice of just asking for the portfolios of designers, picking one and working together. By choosing to have a contest there's a different relationship with the designers.