And for those on Macs? You're dismissing a large chunk of the X-Plane market in your solution here.
Can I ask what products you have made to support your claims? Even if a company takes in their own support, they still have dedicated staff to tend to that matter. Speaking for X-Aviation, considering the premise is quality over quantity, I don't agree with your farming out assessment. In fact, it just happens to show how ill informed you are of how intricately tied the devs that work with us (and vice versa) are from the "ground breaking" to the finished product.
The support forums exist for a very good reason. You can interact with the developers all day long, and if you even pay attention, you'll see people do just that...
As someone who interacts with customers daily in this market, I can tell you first hand majority of people much rather use one channel and point of contact for support as they purchased their product. In the event our support staff cannot answer a question (which is really quite rare), the developer is brought into the support ticket.