If you look at the banned list, you'll see cards that when drawn GREATLY change the way the game is played. It's not so much about how good their abilities are (Kolos, for example can no longer 1hko in ELO, though he's still banned) but how they affect the game (you see a Kolos in your opponent's hand, you are FORCED to play around that card or you lose). Unbanning a character would split the meta into two parts: people using the high-impact card, and people playing decks that have a variety of ways to deal with it. Example: Caelus Cr/Oshitsune becomes unbanned. Result: People start using Tula, Havok, and cards that manipulate attack as an ability. Next result: People play cards that beat those cards, but not the first set. This isn't healthy, it isn't fun, it's just ELO losing a diverse meta and being split into one majority using unbanned card, a minority anti-metaing, and another very small group anti-anti-metaing. Everyone else will lose to the power card decks or the answer decks.

Um, I hate to break it to you, but you are pretty much describing the current ELO and temp bans...

So basically, the temp ban list is the place where cards with one foot in the grave hang out...like an old folks home...and the perma ban list is deadsville. Cards on the temp ban eventually die and go perma ban, opening up room in the old folks home for the new generation of op cards that change the meta when they are visiting the relatives.

I absolutely agree to what Ghnami_LOA said. He sums up the entire argument perfectly. A game focused around playing/countering 1 card isn't fun. I didn't even play elo on Spyke weeks, for example -- it was un-fun.

See any major strategy game -- characters/cards/abilities/etc that define a meta are always banned, because they ruin the variety and fun of the game

See: UR - Spyke
MTG - Jayce, arcbound ravager
League - champion nerfs

It applies around the board