Good article. Some genres do play better on controllers (eg, "beat-em-ups", racing games (though better still on a steering wheel), platformers, etc). But there's no question about the turn speed of a mouse for FPS, or how badly many cross-platform games have been nerfed to make controllers work.
A 180 degree turn in many FPS's typically takes 0.6-1.0s with controller "thumb scrolling" vs a 0.2-0.3s mouse "wrist flick" (which is also the speed you'd turn your head if startled by a noise behind you). That makes a huge difference in the "feel" of a FPS game, not just in competitive MP but single-player too. Some controller turns are so slow it can feel more like driving a remote controlled tank than some super-hero / augmented soldier. Even when you can adjust the controller's turn speed, it often moves the "centre" of the range but the actual "width" of the range itself still remains narrower than K&M. It's basic human physiology that the wrist has more precise fine motor control than the thumbs (hence the need for "dead zones" and
auto-aim cheat mode).
Also well said in calling out how cr*p and lazy modern games K&M support really is - both the input code itself (non-rebindable keys / flaky mouse acceleration often caused by trying to pass mouse input through a "controller simulator") and the knock-on "lowest common denominator" effect that has on UI design, especially RPG's. Eg, Neverwinter Nights 36x quickslots (F1-F12 plus CTRL & Shift modifiers) is impossible to even begin to mimic on a controller hence the dumbing down of modern cross-platform RPG UI's. Dragon Age Orgins (40x quickslots) was probably the last decent cross-platform AAA RPG to be properly optimised for a keyb & mouse when they could (but didn't) "cheap out" on "platform parity". And don't get me started on
how badly nerfed the spell count in RPG's has become, a large chunk of which involves controllers and 10ft UI "casual audiences".
It's often hugely underestimated how much FPS game design has changed too. Controllers = many fast successive turns typical of "old school" shooters are problematic, so "speed is defense" gameplay has largely been replaced with a much slower paced "cover based" system. Level design is now often focussed around fewer but more bullet spongy enemies (reduces turns per 10s), reducing the "arc" from which enemies attack, fewer enemies on-screen at any one time (even modern Doom has far fewer than the 30-50 or so in same room of Doom 1-2, Heretic or Hexen in some levels). Weapon wheels often need to pause / slo-mo down the game during weapon selection, whilst rapid 1-0 / F1-12 keys do not, etc.
The ultimate litmus test is playing old school shooters designed purely for K&M, with a controller via something like XPadder. Gameplay is awful not just because there is no auto-aim but also because the gameplay hasn't been "curated" for controllers. In short - controllers often work on modern FPS's only because the gunplay has been nerfed down for controllers. Personally, I really tried to make the controller work and gave it more than a fair chance over several months, but for virtually everything except racing & platformers, the K&M won every time for me, and only part of that is due to pre-habituation.
