For me, though, it's not about just RPing with others and having open characters. It's about motive and telling a story. It's about my characters, and how they progress through the plot, and how I tell their story -- roleplaying itself is just part of the story. The other characters are part of the story and sometimes needed to complete my character's story overall, but it's about so much more than just roleplaying.
Amy Jacob, for example, my Zarethian. Her story has ALWAYS, since day one, been a vendetta against Eric Mann, a corrupt and now dead Zarethian. My RPing with Lyoko222 and Zak through Amy was because they were people in her life as she progressed in the story of her getting revenge against Mann. Now, UnStellar's character is an important part of that story. Did I plan to RP with UnStellar? No. He made a thread on Tefillin, because it was an important part of HIS characters' stories -- Revenge particularly, and also Faora. Because Revenge's motives led his disciples to Tefillin. My character is based on Tefillin, and her role is Assistant Director, so naturally, she WOULD respond to weird men walking around near senator offices downtown in the Capital. We didn't plan it, but that's what would happen -- and now because of that, Amy has defected from the Zarethians and is believed dead (but she's not really).
My point is simply, don't try so hard. We're not ignoring you. Don't bother asking someone if they want to RP with you, just jump in, they will respond. If they don't, they're either busy or you're not offering much for character interaction.