"Cheap. Fast. Good. Pick two."
Amen to that.
My take is that AMD cards (right now) are too slow to take advantage of 144 Hz monitors
While I see where you're coming from, there are plenty of games out there (and people that play them) that aren't hard to peg a 1440p 144Hz monitor even with a ~$120 GPU. (think F2P games). It's also not absolutely necessary to play the most demanding games with all visual settings on Uber/Ultra/Max which is what most benchmarks use. Most gamers upgrade GPUs every 2-3 years, but keep monitors through multiple upgrades. If anything, I see a monitor as something you can "grow into". That's a harder pill to swallow lately given the recent explosion of improvements in the monitor market (VRR / HDR / high resolution) but it's still worth spending a little extra to get a monitor you'll be happy with for the foreseeable future.
I see your point, but how valuable is it to play a casual game at 144 fps (assuming the game engine can even handle it)?
My experience has been that 120 Hz+ has been very beneficial to me in fast paced online FPS games (I mainly play Overwatch) and not particularly useful in RTS/MOBA games (I play HOTS). In single player games, I have found VRR to be much more useful than the max refresh available, as some games break above 60 fps (Skyrim), some games are capped at 60 (HLD, NieR: Automata), and some games will have a varying frame rate throughout the session (Witcher 3, GTA V, etc). The lower bound of a VRR monitor is also fairly important to me, some cinematics and/or games run at 30 fps even today and can stutter or tear if I don't have g-sync on.
I do find having 120 Hz great for video playback, as it handles 24, 30 and 60 fps content very gracefully. Now you could set up custom refresh profiles in your media player app (MPC-HC lets you do this) to run 72/60/60 Hz respectively, so you don't need
to have 120 Hz+ capability on your monitor, but that is a hassle, and not a solution for browser based playback or closed-ecosystem apps. I could also enable G-sync for video playback, but instead, 120 Hz is a 'set it and forget it' solution for me.
Re: your last point, monitors are advancing much faster right now than at any point in the past 10 years. It doesn't make sense for me to advise 'future-proofing' at the expense of cost right now. Get what suits your current needs, because in 12 months*, there will be something cheaper/faster/better (quantum dots, high dpi, high refresh, VRR, hi-color def, AMOLED, you name it).
* Used to be a good monitor from 5 years ago was as good as a good monitor today, but that's not true now, and it won't be true for another couple years to come, until we reach a new equilibirum/saturation point.
Wind, Sand and Stars.