There are three main reasons why you might want to cut the corn plant’s brown tips:
To stop the corn plant from growing any longer than it needs to grow.
If you cut the brown tips off the corn plant when it’s just sprouting, the plant will have a hard time putting its energy into growing, instead spending more time trying to recover from the stress of being cut off at the roots.
The brown tips serve as a way for the plant to send nutrients back to the roots. When the plant is done growing, the leaves fall off and are replaced with new ones. The brown tips are the plant's way of telling its root system that it’s time to start growing again.