Why is it dangerous to ride a motorcycle with worn, cracked, or aged tires (dry rotted rubber)?

1. Aged rubber hardens and loses adhesion, risking sudden structural blowout, tread separation, and catastrophic loss of grip in turns
2. Aged tyres are safe as long as the tread depth remains above the minimum
3. Cracked sidewalls affect appearance but not the tyre's structural strength
4. A tyre that has been little used stays in good condition regardless of its age