...Many of the add-ons with high ratings already have their developers signed up on XF.
Many of them should -stay- as add-ons as well, as functionality is more likely to get added to those then it is if it were a core feature, due to the workload Mike and Kier will already be facing, and with everyone wishing them to adopt additional official premium add-ons asap.
Yeah I've noticed that add-ons that aren't very useful sometimes get a lot of downloads on vb.org while some really useful ones aren't as popular. You can't use this as your main system. I think we have a good system here: a suggestion receives likes and replies (discussion) and then the developers can see if it could fit in.