Dude I've wanted that stupid card banned for
almost 4 years. The archetype does incredibly fucked up things to the format- a Vault/Key deck that operates at instant speed and lets you tap an opponent's land down is not fucking fun at all and warps everything around it. It mandates cheap instant-speed creature removal. It negates the ability to use life gain in the format. It and Pod created an issue where a giant # of games ended in an arbitrarily large combo damage kill, which is incredibly bad for the metagame.
The problem is that none of these things are obvious, and because the deck existed in Standard for 6 months and didn't "run things over there", people do not see it as an issue, despite it winning a Pro Tour in a field full of decks that were ostensibly "much more broken", like Cloudpost and Blazing Shoal Infect. Banning just one critter also does not work- Village Bell-Ringer can be subbed in. It's an archetype that should have been scourged off the face of the format years ago and has made the format so much less fun because of it's existence. No combo deck in Legacy feels this obnoxious to play against, even with decks that operate at Sorcery speed.
I know you don't like it, but you're not making any real case for what that means it should be banned. If the problem isn't obvious, the deck isn't taking over the format and it's not winning most tournaments, then the deck is not ban worthy. I'm sorry, but you've only made the case that the deck is great, but not oppressive.
Yes, it makes you play against it differently than other decks. You have to be careful around turn 4 or risk dying. You have to hold removal rather than just mindlessly flinging your spells out at the first threat. (And name me a modern deck that doesn't mandate cheap creature removal. Path and Bolt are in like, 60 percent of all modern decks and that wouldn't change one iota if Splinter Twin was never printed. )
It's a highly variable deck that demands you pay attention to what the other player is doing. That's part of what makes it an essential part of the health of a format that otherwise would be overrun by Jund or Abzan formats. You're talking about the deck like it's a much bigger problem than the facts support.
And considering you take issue with the deck's combo kill, and Infect and also Pod, it's clear you simply have issues with combo decks in general in the format. Which is totally fine, mind you, that's not a knock, but it's worth mentioning that combo is a legit strategy that has to be represented for the format to stay healthy, contrary to what you're saying. Without combo, you have aggro, midrange and control only. Talk about boring. Combo adds a new wrinkle to the meta and while it's the strategy that needs the closest eye kept on it, as long as it's not oppressive I think it's necessary.
And do I have to point out how absurdly over the top the "no combo deck in Legacy feels this obnoxious to play against" comment is? A deck that can kill you turn if you don't see it coming is hardly on the level of Tinker or Vault/Key.
They're going to keep printing more and more cards that slot into the deck- trying to "soft ban" it isn't really going to work once you get a majority willing to take action against the deck. Better to rip the band-aid.
You keep saying this about every deck, btw. Every deck keeps getting more cards that slot into decks. That is not a reason for or against a banning. Every deck continues to get a growing pool of cards. There is no band aid to rip off, it's the normal functionality of the modern format.