The only comment I can add I guess is to just remember that polyamory is still a little know & understood concept in the masses. Add to that a broad perception in the general public that such concepts usually end in some kind of drama and disaster, and you can understand why it's a difficult struggle to try to "find" the right connection.
And maybe that's a big part of it too. I think most people who find themselves in some form of successful poly relationship will tell you it didn't happen by design - but almost by chance. Often spawning from some existing friendship that developed for other reasons. Others I know have just advised you go about living your life with the awareness that any person you happen to come in contact may develop into a deeper relationship.
Only when the knowledge of successful poly relationships becomes widespread will this mis-perception be dispelled.