I see your point, but I also disagree with it because I know what ADCs are like as a support main.
The support needs to be able to do a lot with very little.
- We don't scale well. We're usually 2-3 levels behind the enemy support. This creates issues for a lot of "off-meta" high damage supports. They fall off hard if they can't get the cheese early game. So I do see what you mean, less so now that I'm back in Gold.
- Our income is the lowest out of all roles. You aren't going to be able to afford those big ticket items that make most off meta champions shine. On top of that you need to buy Sightstone, so that's 800 gold you need to give up already. All it gives you is vision and map control, but that's so crucial for the game and role.
So yeah playing Katarina Support isn't the best idea. What I see more often is Brand and Annie supports, and boy are they still making a risky pick. They're assuming that they can get ahead early, and those of us that spend most of our days bot lane know that wonky stuff happens. You winning your lane is not a given, and if they can get to 6 unharmed, your pick goes downhill from there. I know what kind of player you are when you pick those kinds of supports, and I'm going to act accordingly. It is usually best to pick a high utility support that isn't useless if they don't scale fast, but still those picks aren't completely useless.
At the same I hate when the ADC tries to dictate what you play, with a passion, and I don't even play off-meta supports. My main supports are Soraka, Janna, and Leona.
Play Braum
Braum wins games
Bans your pick because you didn't pick Braum
A support pick usually isn't the reason you lost. When a support gets an ADC that is having a bad game we usually can't do much else besides ward for them and roam, hoping for the best. We're designed to create opportunities for the team to make plays, so if you can't even kite that's a bit of a problem for us. When you realize your ADC can barely farm, doing anything more will result in your death or both of your deaths.
An ADC has damage, if they can focus on farming, even if they get bullied out of lane a lot and pushed under turret initially, they can make a comeback late game. They do damage, and they scale. Your chances aren't entirely tied to how well the support is doing. That's why the support role is least popular, and that's why so many people turn to KSing supports in Silver. Getting creative and trying to reshape the game is a lot more difficult as a utility support when your team is failing because this game is built around damage.
Someone playing a basic functioning support is the bare bones, and you can do just fine with any champion watching you farm and warding for you. I don't believe you lost because of a support pick unless they fed like crazy. You're going to get so much further when you stop blaming others for how you play. You're rarely going to have the perfect teammates, trust me.