My question is pretty simple - Why?
Whether you like it or not, moving forward I believe ESRI will retire ArcMap (very soon, say 5 years time) and there will be only ArcPro. I can understand the feeling when you are so use to with ArcMap and all of sudden when you struggle to find the same tool that you have used for years in ArcMap into pro, it is very obvious that you would hate Pro. ArcPro from beta through to 1.3 now has improved a lot and Esri is giving their best to improve (I believe so, for their own benefit). Needless to say, Esri's product chokes at times but I have more good things to share than bad 
I shared this question for a couple of years. But no longer. I'm nine days into a cold-turkey quit of ArcMap. Big user requests that have been put off for years by Esri are showing up implemented and stable in Pro 1.3 like: Design view for attributes. Rename and reorder your fields, yes; and not just aliases! Tweak one or twenty items, then Save those changes to a revised schema. People have wanted that for more than a decade, and now it's here.
Consistent, more purely Pythonic approach to geoprocessing. I was a bit put off at first by having to go to the little red lunchboxes so much to do my stuff, until I realized that that Geoprocessing pane was accumulating my last 20 functions and suddenly I stopped hunting. Everything is Python, so instead of calc'ing in some <NULL>, its now called 'None' and the single quotes are not needed. That works for me.
Lots of editing for me this past week on building footprints; quickly I find a workflow like select in attribute table, Zoom to Selected is right there, Merge stays open and docked, then on to the next one. This is nice! Split polygons with or without a selection? I'll take three of those!
Want to get started in 3D? Finding the Procedural renderers without need for a CityEngine license really makes my day. And when that fancy rendering is taking place, my workstation is firing on all 8 threads and yet the interface stays pretty responsive. That ain't never gonna happen in a 32-bit app that derives from MFC tools released in the Windows 95 era.
For myself, after less than 10 days, I'm only going back for very specific things: ArcGIS 10.4.1 for Desktop gives me more stable ability to join 16 attributes from three different tables to 150,000+ polygons, so I use it for that and get right back to Pro. Creating a new Feature Dataset that is defined for both local horizontal grid and also for standard Z datum? That is doable in 10.4.1 and I can't figure out how to specify Z in Pro 1.3 right now. But in 10 days, that's two *very* narrow actions that were better in Desktop.
By way of disclosure, I learned Arc/INFO at 4.01, found reasons to use ArcView GIS from 1.0 to 3.2a, and saw Jack Dangermond outshine Steve Jobs at the plenary where 8.0 was announced. So 16 years with a 32-bit app really does seem long enough to file for separation without too many regrets! Maybe keep trying?
