Why is Zigzag the only good red defensive?

[Valgar]

Will not call you shitter, here is my point of view :

Green Unarmed is OK tier to start
Yellow Unarmed is underpowered in all aspects (Haymaker and Kick are a joke)
Blue Unarmed is meh what is this color ?
Red Unarmed is "Im melee now and only needing Knock his teeth out"

Not talking about Melee you just did it.

[yym331]

This is jorbtar's idea of balance
Red has
- the best IP generator (qb)
- the best opener (kito)
- the strongest finisher (cleave)
- the cheapest finisher (fc)
and to top it off, the only way to reduce it is to give your opponent IP
Yes, it's perfectly balanced.
Before calling me a shitter, compare kito and kick.

To be honest, there are plenty of issues beyond Zigzag. For example, when comparing Kito and Kick, Kick is an incredibly weak skill, and there are many other skills that feel like a joke in terms of effectiveness.

Rip Apart, the highest-cost skill in the UA deck, is completely useless compared to Takedown and Jugular, which are much stronger. Personally, I find Go for the Jugular to be a ridiculous deck compared to Kito. In the past, it had a dedicated Defences card called Yield Ground (although it was impractical and rarely used), which provided +10% Off Balance and +15% Cornered, creating a reasonably efficient set of Openings. However, now it offers +10% Reeling and +15% Cornered, which are the less desirable red and yellow types, resulting in a total Opening of only 25%. This makes it a rather poor deck overall.

I think the game would be much more interesting if there were more viable decks. (I understand that combining UA and MC with Parry can make for some fun and creative gameplay.)
While it's not necessarily bad game design that OP, Kito, and Flex with Cleave are the most effective setups for showcasing player skill, it's also true that there are decks that feel poorly thought out.

[Reiber]

This is jorbtar's idea of balance
Red has
- the best IP generator (qb)
- the best opener (kito)
- the strongest finisher (cleave)
- the cheapest finisher (fc)
and to top it off, the only way to reduce it is to give your opponent IP
Yes, it's perfectly balanced.
Before calling me a shitter, compare kito and kick.

but in turn. red also has one of the most efficient defences against it.

[it-Tato]

This is jorbtar's idea of balance
Red has
- the best IP generator (qb)
- the best opener (kito)
- the strongest finisher (cleave)
- the cheapest finisher (fc)
and to top it off, the only way to reduce it is to give your opponent IP
Yes, it's perfectly balanced.
Before calling me a shitter, compare kito and kick.

To be honest, there are plenty of issues beyond Zigzag. For example, when comparing Kito and Kick, Kick is an incredibly weak skill, and there are many other skills that feel like a joke in terms of effectiveness.

Rip Apart, the highest-cost skill in the UA deck, is completely useless compared to Takedown and Jugular, which are much stronger. Personally, I find Go for the Jugular to be a ridiculous deck compared to Kito. In the past, it had a dedicated Defences card called Yield Ground (although it was impractical and rarely used), which provided +10% Off Balance and +15% Cornered, creating a reasonably efficient set of Openings. However, now it offers +10% Reeling and +15% Cornered, which are the less desirable red and yellow types, resulting in a total Opening of only 25%. This makes it a rather poor deck overall.
100% there are tons of issues with balancing between skills to the point where a lot of abilities just overshadow others and you would just never use them. Kick is entirely overshadow by kito. Zigzag overshadows everything else that drops red. the basic blue and green defensives are also pretty hard to drop for something else.
I think the game would be much more interesting if there were more viable decks. (I understand that combining UA and MC with Parry can make for some fun and creative gameplay.)
While it's not necessarily bad game design that OP, Kito, and Flex with Cleave are the most effective setups for showcasing player skill, it's also true that there are decks that feel poorly thought out.

You are not wrong. there are a ton of abilities that overshadow others entirely. Kick vs Kito and zigzag vs everything else that drops red just might be the most egregious examples.