Hindus/Sanyasi a one way traffic
Why sanyasi is a one way traffic?
One become sanyasi to master advaita. After mastering advaita, if one want to give up sanyasi and leave like an ordinary person. Can he?
There are two stages in renunciation. First is called Bramachari and the second is Sanyasi. For studying the scriptures, one is supposed to become a Bramachari and not a sanyasi. After mastering Advaita, there is a choice. One can return to normal life of a family person (Gruhasta) OR take up sanyasa. If one has decided to take up sanyasa at this stage, then he cannot disrobe later.
Personally, it does not make a difference to a concerned person whether he continues to be a sanyasi or ordinary person. But it affects the society. The public in general and the students in particular has lots of reverence to the sanyasi because he is a sanyasi. Suddenly if a sanyasi decides to disrobe it will affect the spiritual progress of the society/students. That is the reason why scriptures provide an injunction that once a person becomes a sanyasi he/she cannot disrobe.
A sanyasi has many privileges. For example, he need not (should not) earn any money. It is the duty of the gruhastha to support a sanyasi. After enjoying such privileges, one should not disrobe.
The purpose of becoming a sanyasi is to serve the society. It is a commitment given to the society which cannot be revoked.
Thanks for asking this question. If you need more clarifications, please let me know.