In Jainism, truth is bigger than any label, including the label “Jainism.” Jain Dharma itself says that the purpose of right faith is to understand yathārtha tattva — reality as it is.

But from the Jain philosophical view, the point you raised about karma is not accepted:

• Jīva (soul) is not material.
• Karma is also not just an illusion; it is a subtle form of pudgala (matter).
• Bondage happens not by gross physical sticking, but through association, vibration, and passions such as rāga-dveṣa, kaṣāya, and yoga.
• So Jainism does not say the soul becomes material or that karma sticks like mud on a wall.

The correct Jain view is:

1. Soul is eternal and formless.
2. Karma is material but very subtle.
3. Bondage is due to the soul’s deluded activity, not because the soul is itself material.
4. Ignorance (mithyātva / avidyā) is the root of bondage, but karma is still considered real, not merely apparent.

Your example of blue sky is useful only as an analogy for misperception. But Jainism would say karma is not merely a visual illusion. It is an actual subtle bondage that affects the soul’s knowledge, perception, and experience.

So, in Jain terms:

• Truth is higher than sectarian identity.
• Jainism claims to teach that truth.
• If any understanding of Jainism seems to conflict with reality, Jain philosophy would ask for deeper scrutiny of that interpretation, not blind defense.

If you want the shortest answer: Truth is bigger than Jainism, and Jainism should stand or fall by truth.