If the shoot is cut too close to the main plant, why won't it grow any roots?

Question

If the shoot is cut too close to the main plant, why won't it grow any roots?

Answer 1

Maybe because, the shoot mainly needs nutrition from the main root, which means that, it DEPENDENT to the the main plant for nutrition and stuff...

That is why sometimes, if you want to cut a shoot and plant a new one from it, you must ensure that it is not dependent to the main plant and can live on its own and make its own roots

Answer 2

Because the shoot cut that way has no growth node at the bottom of the cutting. The next node my be too high up.