About Zenons recent statement regarding "Counterplay"
"A button that says "I remove this effect" is not counterplay. A button on an item you have to buy that says I remove this effect is even worse. Look at any time Malzahar/Warwick/Skarner are strong in the meta--you now have to buy a QSS if you're a squishy on the enemy team. This is not counterplay, this is just forcing people to buy a suboptimal item. Counterplay is Morgana's Dark Binding hitting minions and traveling slowly and having a cast time. You can stand behind minions, dodge it, or worst case situation flash away from it. Counterplay is Gnar's big form having bad mobility, forcing Gnar to hop/crunch in for the GNAR! when his rage is almost full--talk about a well telegraphed engage. You can see it coming, you can spread up, you can slow him down, you can kite back etc. Knock-ups are no less or worse in terms of counterplay than stuns or roots. That they're unaffected by tenacity and can't really be cleansed (they CAN be cleansed, at least the part that makes you unable to cast/attack. You're still considered "in a move block", so you can't move by right-clicking, but you can, for instance, cleanse an Alistar knockup and Lucian-dash away from it while you're still in mid air) (but this is academical and besides the point) is an artifact of implementation that was later embraced as intentional. We could totally make the choice that tenacity shortens these effects or that cleanse drops you to the ground instantly, but it's not entirely obvious if that would be a net positive. TL;DR: Counterplay happens before you are hit by an effect."
While I personally agree on some parts of your argument...I don´t think your TL/DR is healthy for the game:
- for me Counterplay means that you have a chance to punish your opponent if you manage to outplay (e.g. dodge his ability). THis is sth. that just doesn´t happen for a lot of things in this game currently, old Nida had been a prime example - as everyone noticed that it´s not really counterplay to stand there and dodge spear after spear for an hour with little chance for her to screw up and be engaged on while she won if you just screwed up dodging once. The Morg Binding you use in your Example for me falls in this category actually: Yea, it can be doged and it can be blocked, but in the end of the day it does not offer you any chance to strike back at Morg if she wastes it - she still is 1000+range away and has her balck shield to save her from serious engaging attempts. So the Changes for her to screw up are way less than the changes for someone to finally get hit and then stay CC´d till doomsday. I think you really should reevaluate how impactfull you want to have such spamable long-range skills...and especially how much disengage potential you want to hand over to Champs that have such long-range abilities.
- So as
does not offer any Counterplay to anything his main function then somewhat seems to be to make Varus and Ashe (carries that realy on their initiating utility) unviable currently. I think the Game would actually be better off without that Item and your arguments sort of support this. - Alistars ~90% pick&ban-rate in worlds currently really suggests that Knockups/backs are really worse to play against than the likes of Stuns. E.g Irelia should be a natural counter to toplane Alistar, as she deals truedmg, has great sustain and is really resilent to CC - though well, turns out she´s not resilent to being knocked around and thus just cannot dare to face Alistar. I think Counterbuilding is still a large part of Counterplay in the long run, and right now you really undervalue the impact of Tenacity on Teamfights way too much...while hardcountering certain things with the likes of
or die to it surely isn´t a healthy way to deal with things - soft countering CC by bringing the duration you have to live through down before you may impact the fight again really helps out a lot, especially on frontline Champions (though they seem to be fairly neglected anyway ever since S2 ended)

Blade of the ruined king?
which is niche, but isnt so well-rounded that it feels like a must buy that does too much. Youd only buy it to fill the niche, which I feel like BotRK should be, niche.
is strong, but niche. Outside of this niche there are other items which fill a general purpose perhaps
better, but do not fill the same niche that thornmail does.
of items.