In Jain Dharma, a Tirthankar does not stop all himsā in the world because he is not a controller of the karmic order. He is a path-shower, not a force that overrides the karmas of living beings.

Why an ordinary follower may stop one act of himsā

If you save an insect from being eaten by a spider, that can be a small act of dayā done without hatred, and it is good when done with:

• no violence in mind,
• no pride,
• no attachment,
• and as far as possible without causing greater harm.

This is within the conduct of a householder or even a seeker, depending on the situation.

Why a Tirthankar does not “interfere” in the same way

A Tirthankar is:

• vitarāgī — free from attachment and aversion,
• sarvajña — omniscient,
• kevalī — beyond delusion,
• and completely established in the nature of the soul.

Because of this, a Tirthankar does not act out of preference, anger, pity, or personal will. He does not say, “I like this creature, so I will save it,” or “I dislike that harm, so I will stop it.” He remains in perfect equanimity.

The key Jain principle

In Jainism, each soul experiences the fruits of its own karma. A Tirthankar cannot cancel another being’s karma by force.

He can:

• teach ahimsa,
• show the path of liberation,
• inspire right conduct,
• and awaken beings to restraint.

But he does not rewrite the karmic consequences of all living beings in the world.

So why is this not cruelty?

Because in Jain view, a Tirthankar’s highest compassion is not emotional intervention in every event, but:

• revealing the truth,
• leading beings away from bondage,
• and showing the means to stop future himsā.

Saving one insect may be a good act for you, but a Tirthankar’s mission is far greater: to free countless souls from the cycle of bondage itself.

Short answer

You may stop one himsā act as a practice of compassion. A Tirthankar does not do so as a personal intervention because he is free from attachment and aversion, and does not violate the law of karma. His compassion is expressed through teachings, not through selective worldly interference.

If you want, I can also explain this from the perspective of dravya, bhāva, and niyati in Jain philosophy.