Context
Back when Rylai's was changed, some people includeing my self already voiced concerns.
However, thx to the rather bad state of mages overall, Rylais was a rare sight in most peoples games, and in pro play it were victor and azir, tow champs that are kinda broken on their own and naturally synergies well with the item, so no one cared muctch about them useing rylais and beeing strong, so that metter was fast forgotten and the general opininion was that it were outliners that got nerfed acordingly(like Eve)
However, since the mage update, mages are seen much more frequently, and most of them, especially those that see competetive play, do use rylais as a core item.
People only complain about what they see frequently, you rarly see comlaints about champs with very low pickrates either, and once the get popular for whatever reason, everone comlains about all the things that the said always did.
Like ekko for example, a small buff to his Q cd in early ranks and some people notice his early lane is quite strong, experiment with tank builts and suddenly we have tank ekko, who does the exact same thing that ekko did since release, and everyone gets hysteric about it.
Also, there are usually other things that are more urgent for most players, sp they complain about that and ignore rylais or what ever other issue lurks around for the time beeing.
Dynamic que for example der alot attention away from other things, and now the hysterie about that is slowly declining so other subjects get more attention on the forums.
And the Rylai's discussions didn't come up on their own own, but as a 'sideproduct' of other threats that are in some way related to Rylai's
The azir nerfs that have some people guessing if nerfing Rylai's instead wouldn't be the better call, in a threat about garens declineing winrate since the mage update many came to the conclusion that Rylai's plays a big role in that, And in some discussions about the boots of swiftness nerfs, many argued that the boots where mostly so popluar because of to many slows and naturaly some draw a line from there to Rylai's.
This is the standart procedure with items, usually it needs quite along time till they are indentifyed as broken, most of the time they the main users need to be the current meta champs for the items to be recived as overly strong, and it needs to be many useers, or users that usually aren't expected to buy that item, else the champs are seen as the issue and not the item that they all built(though it's always a delicate queston to what extend one should balance **around **items and when one should start balanceing the items themself).
The juggernaut items are another example for that, there were only very few complaints about titanic or deadmen's when they got released, people belived the reworked juggernauts were the issue at the time but serveral months later they were used on many champs and soon other champs as well as the items got nerfed.