Why do people suddenly think a really long, narrow body is a good idea for domestic flying? No carrier locally operates the 737-900 and it already takes an eternity to offload a 737-800 at Qantas. The 737-10 still only has one FWD door I believe so it’s not going to have a quick turnaround.
Good aircraft for some routes no doubt, short-haul international stuff probably, but I doubt you’d want it as your main domestic workhorse.