I think this project was put into works > 1 year ago. It's obvious it wasn't designed to incorporate Moments, the no character limit for DM's and Polls (all new features from 2015). Building out a Mac app shouldn't be a top priority of any company today, unless you're into productivity (i.e. Sketch, Adobe).
I'm almost sure that Twitter was stretched thin with Obj-c/Swift engineers building out the iPad app and refreshing the iPhone app (Moments) this past year.
I'm almost sure that Twitter was stretched thin with Obj-c/Swift engineers building out the iPad app and refreshing the iPhone app (Moments) this past year.