That´s like saying every single ADC isn´t mechanically intense, despite the role being recognized as one of the most mechanically intense ones.
So yeah, Kayle is mechanically intense, just not in the way you think. You can´t kite or orb walk or correctly time your ult? You die. That 2/2.5/3 second invulnerability isn´t going to be enough to make up for the lack of kiting/orb-walking skill, which, be shocked, is a requirement to be good with any ADC.
Also, in comparison to Lee Sin, Kayle is underloaded at best. She's slow, squishy, vulnerable to ganks, only a real threat after 3 full items, one of those being Zerker's Greaves which gives her AS but does little to decrease her susceptability to ganks.
And let´s not even get started that, in this cancerous as hell top lane meta, where tanks build Sterak's, DMP and tank a 6-item ADC+Turret aggro, where Ekko build builds Sunfire and outdamages a Lich Bane Fizz, she's the only one who can deal with them and make them actually stay top lane so she doesn´t bring down two turrets with just a Stinger.
I would much rather have them reduce her passive ArReduction rather than outright remove it. Have it only stack up to 10% and move the 5% into the MR reduction. Despite all that and being a biproduct of the meta, she's only strong because of Fervor and Guinsoo's.
Riot isn´t nerfing the problem, that being the top lane meta. Riot's nerfing the ingame SOLUTION to said problem. Much like they´re nerfing IBG in the Spellblade rather than just make it melee only, as they should be doing, so that Ezreal stops abusing it.
Much like they completely butchered Soraka's kit simply because of her heal spambot status and being supposedly cancerous. Still think healers should have HP scalling heals, rather than AP scalling heals.
Anyway, back to Kayle. You´ll rarely see a Kayle using ranged to stack Rageblade. She´ll stack it in melee mode because it grants 2 stacks. On some occasions it´s the same for Fervor. Again, she isn´t the issue, but double stacking speeds is.
Sated is a problem nowadays on, surprise surprise, melee champions, because the phantom hit is unchanged.
Guinsoo's is a problem and therefore making Kayle, Xin, Yi, Jax, Trynd and once, Irelia a problem because of the 2 stacks for melee.
Fervor is the same issue as Guinsoo.
How should Riot be solving this?
Nerf Guinsoo's. How?
Ranged AND Melee champions now only get one stack.
Reduce AD/AP/AS per stack to 2, 2 and 6%, respectively.
Guinsoo's Rage: Deals 15(+10% Bonus AD)(+5% AP) as opposed to the current 20(+15% Bonus AD)(+7.5% AP)
Next, move on to Fervor.
Reduce stacks to 6. Reduce damage by 2, maybe 3 or 4 points. Ranged, melee and abilites now only grant one stack.
Onto Sated next.
Melee and ranged only proc phantom hit on the 4th AA.
Reduce magic on hit damage to 20 on normal Devourer. Totalling 50 on Sated.
Kayle did need a nerf yes. But they´re nerfing her the wrong way and not even addressing considerably more urgent balance problems first.
top vs a graves, and had to give up a couple cs bc of the range issue but it isn't as big a deal as you make it out to be.
and 
(mainly his stupid early game) are much bigger problems?
get all the stats from items while the previous one abused her passive.
are playing her too much. >_>
and 
justs shred a flat amount in a meta where people look for an excuse to build a mr item?
