Minos (or, more accurately in most versions, Daedalus) wants them to take this dangerous risk because it is the only real chance they have to escape the Labyrinth and avoid being trapped forever.

Who says the plan is dangerous?

In many school texts and worksheets, the line is written as “Minos tells Icarus that the plan is dangerous,” but in the original myth it is Daedalus who warns Icarus.

Daedalus explains that the wings are made of feathers and wax, and that flying too high will melt the wax while flying too low will drag them down into the sea.

Why take such a risky plan?

Even though the plan is dangerous, Daedalus wants them to take the risk because:

  1. It’s their only way out.
    They are imprisoned on Crete, in or near the Labyrinth, and there is no safe path by land or sea because King Minos controls both. Escaping by air is the only possible option, so the danger is worth the chance of freedom.
  1. Staying is actually worse.
    Remaining in the Labyrinth or on Crete means a life sentence, “staying in the Labyrinth forever,” so Daedalus believes it is better to risk death for a chance at escape than to live as a prisoner with no hope.
  1. He trusts his own skill.
    Daedalus is a master inventor and believes his wings can work if Icarus follows his instructions, so the risk feels calculated , not random. He warns Icarus carefully and expects him to obey the rules of flying in the middle path.

A common way students answer this in class is:

He wants them to take the risk because it is the only way they can escape, and he would rather risk danger than stay trapped forever.

Extra angle teachers often look for

Teachers also sometimes expect you to mention the theme :

  • The myth shows that sometimes people must accept risk to gain freedom or a better life.
  • It also warns that even a smart plan can fail if you ignore wise advice, which is what Icarus does when he flies too high.

TL;DR:
He wants them to take the dangerous risk because it is their only chance to escape King Minos and the Labyrinth; staying is a worse fate than risking the flight.

Information gathered from public forums or data available on the internet and portrayed here.