I think it would be extremely helpful if we had people stop telling us what to do with our modifications, both in terms of whether we charge for them or not, and deciding what modifications should do instead of just merely make a suggestion and letting the add-on developer decide. Oh, and stop giving us flack because they don't like a certain way a modification is done.
Otherwise, what do I want from XenForo? Nothing more than what they're already giving. Kier and Mike have provided a very, very nice platform to work from, and they and other people have been massively helpful when it comes to answering questions or providing examples. The add-on community may not be large yet, but that's because XenForo is still new. I imagine there's also a few people who aren't touching XF yet because of the lawsuits and want to know which way the wind will blow before they start to invest serious time in it. I think there's probably even a smaller percentage that would like to, but don't have the knowledge or experience working with XF yet, or are perhaps busy with their own projects elsewhere (like at vB or IPB).
Give it some time and they will come. You seem to be expecting a massive developer community vBorg has, which took years to grow, in a few weeks here.