Consistently banning off-meta strategies in the support role seems to be the poor way to go about it.
If anything, you're only reinforcing the purpose that you're the ADC's bitch.
Nobody wants to be someone's bitch.
[zombie-brand-facepalm]
It's more about making the intended champions of the support role more attractive.
The support is meant to support their team. Usually this starts in bot lane.
The issue of the current support champions is that supports have more income and slot efficiency. This makes the flaws of the role from previous seasons less noticeable and create supports that can scale well with items. You would never see a Zyra support in season 3 with actual AP items. Now you see rylais/liandry Zyra supports all the time and manage to get highest damage in the game with the least amount of gold.
The problem is normal traditional supports never really benefit with more AP or stats in general. They tried doing AP ratios on utility spells, but they were fairly insignificant or blatantly OP.
Riot tries to fix this by adding super impactful active items like Zeke's Harbinger but it ended up being outdated the next season. Then this season introduced redemption and locket which is pretty much a must buy as the actives are insanely strong. While the stats they give are very lacking it made those actives more impactful than the actual support champion itself.
My idea of an ideal support champion is one that doesn't really need items to function with bad ratios but good bases. This way supports can be stronger than an ADC early game but not end up outperforming everyone else in terms of damage later on. Have spells be focused on more interesting effects instead of generic CC or shielding/healing. Items for supports would only function to give them a few extra options in team fights that isn't just use this active during a fight. Have it require actual timing to make it work.
They're not reinforcing that Support players should be the ADC's bitch, they're reinforcing that if you want to do something heavily off-meta, that you have to communicate it with your teammates. It's not "Support players should be the ADC's bitch", it's "People should work with their teammates if they're going to do something like duo-jungle Nunu" - especially since such a tactic left a bunch of ADC's at a disadvantage because they were up against two people with practically no help for the first few minutes.
And they're not consistently banning off-meta strategies, either. I mean, I don't see anything big popping up about some Malz Support being banned, do I? Singed and Nunu are edge-cases, it's not consistent, nor is it for the reason that they were off-meta: It's because they made their teammates miserable for the sake of winning.
