I don't list my interests on my facebook profile, nor do a great many of the people on my friends list. For some that is because they don't want facebook having this information, for others, they simple can't be bothered entering it.

I don't think you can classify this as "using it wrong".

It seems obvious that if I or a user like me were to use this service it wouldn't work very well, and would potentially devalue the service for other users (through poor matches).

The developer of the service is artificially limiting their market by only allowing Facebook Connect and they may have problems getting the necessary critical mass for the service to be useful as a result. I don't think it's trolling to make this observation.