We look at it the other way around. What reason was there to list it? What information did it give that we couldn't find from a more reliable source?
When we couldn't give a good answer to THAT question, rejection was inevitable. We never need a reason to reject: we always need a reason to list.
But more than that, this is fundamentally a kind of site that we have made an editorial decision not to list: not only does it not contribute to the purpose of the ODP, it can reasonably said to conflict with it.
As to when you can submit again: please, never, until you can look at it from our perspective.
What's our perspective? Well, the site submittal form is there to allow people to help us sites that meet our criteria. It's public because we accept help from anyone.
But -- that site wasn't a close call! if someone doesn't understand our criteria well enough to see why IT wasn't of interest to us, then they really aren't going to be able to help at all. Anything they do will almost certainly waste both their time and ours.
The decision is always in your hands. There are no arbitrary limitations of any kind placed on your actions. For that matter, we don't attempt to place any limitations on your actions. We only give information.
But submitting without understanding that information is counterproductive--it doesn't accomplish the intended purpose, but it does affect your reputation.