The extensions in AMO get a human review so they tend to have a higher quality and less malware that is why extension malware tends to hit Chrome more than Firefox. This is really cool for users but it sucks for devs.
Mozilla offers another way of distributing your extension: on your own site. They are called unlisted addons, don’t need a human review and get all the benefits of listed exceptions like the fact that they are digitally signed, you can push updates and so on. They don’t get to be listed in addons.mozilla.org.
I personally trust extensions from AMO more and I try to avoid unlisted extensions. Here is the list of differences between listed and unlisted.
If you wish to have an unlisted addon I can help you if you have any issues but I think it is a lot better if you are a little patient and wait until the review is done. You have options…you choose what to do.