Because it's the only non flier skyfire in the codex. And it's still damn effective for its points. Losing its jink ignore was pretty necessary to keep its points down, and the open top bit is largely irrelevent. They're still extremely strong AA, unless you're just going to rely on your 6-9 divination psychers and weight of dice to bring down air now instead.
Losing "Ignores Jink" didn't need to be removed keep the points down, at least not as long as it doesn't have Interceptor.
I'm actually reading a number of Guard players who aren't sold on either model for a number of reasons, meaning neither of these kits really looks like a "hot seller".