I'm basing my comments here on what I've been reading on other gear-oriented sites. A majority of Nikon DX system buyers tend to be low end consumers who will likely never take the basic kit lens off. So there's not much of a specialized DX lens market for them. More serious DX shooters tend to move up to FF. The remaining (DX) D7_ _ _ and D500 users might benefit just as much from FF compatible lenses so that they don't have to eventually undergo a complete system change when they move up to FF. The hole left in Nikon's DX line is mostly a lack of DX-specific wide angle and ultra wide angle zooms and primes. These would be expensive to design and produce. The numbers just wouldn't be there to make it profitable. Talk on other gear-oriented sites is that mirrorless FF is the coming tide. If Nikon and Canon want to get on board, that's where you can expect to see new lens designs go. Consumer DX is still very popular and profitable for Nikon, but maybe not in the long term when people will find more compact advanced mirrorless cameras with FF sensors from other manufacturers, with Sony already in the lead. A market for pros in Nikon FF DSLRs will remain, according to the gurus I've seen quoted.