The fact is that guys/people today are very busy, and they use all kinds of code words to protect their free time and still be "nice." This guy doesn't want to spend time with you, and is using the "spark" excuse even if you're not looking for more than friends. Everyone, including you, tries to manage interactions, but I know it doesn't feel good when you're on the other side of it. Just move on, there are plenty of great guys out there (you appear to be one of them!), so why waste time with someone who doesn't seem to want to spend time with you?!
Not that it's comparable at all, but here's an instance of where you were potentially limiting your own time spent with someone you didn't want to waste time with. In April, you wrote an interesting post on "sexless relationships." I wrote you directly with a fairly long and thoughtful response. I wasn't hitting on you in the least, was trying to be helpful, but I had zero response from you. No drama, I get that people are busy, and that was that.