Why no upgrade pricing?

I bought AirDisplay when it first came out and loved it. Then Apple updated iOS and it broke. I bought the upgrade (since no free upgrade was offered). It worked until Apple upgraded MacOS, then it broke again. I was able to download the Mac part for free, and once again, it worked. Now, I upgraded my iPad to iOS 9 and AirDisplay broke again. Now, I have to buy another copy (no, no discounted or free update) to make it work again. ENOUGH ALREADY. I rely on your software, but even Microsoft and Adobe offer upgrade discounts. I also dont think that I should have to buy a new copy every time theres an operating system change. How about offering your licensees a free or discounted update path? Now, Im switching to a USB monitor in lieu of paying for another update.

PMH75 about Air Display 2