Public Domain Super Heroes

It is great this site is devoted to Public Domain characters.  However, I am a bit reticent to visit the site because of the plethora of Open Source Characters.  

Yes, I did contribute to the design of one Open Source Character but the issue I have, is this site seems to have too many Open Source Characters.  I am saying this because I get the distinct feeling many of these characters weren't really intended to be "free" but for the potential of someone eventually claiming "rights" if a creator decides to use them in their potential publications.  

Really HATE to think along those lines but it just seems there are too many Open Source Characters.  Don't get me wrong, there are many great ideas, characters and names but again, I am really wary of all these characters now.  

Am I the only one thinking it? Not trying to be an ass, not jealous by any means, just wondering if I am "off" with my opinion here.