Anything powerful should be handled carefully. If we don't handle them properly it would create havoc and disaster. For instance, if we get a flammable substance we wouldn't put it anywhere carelessly. We would put it in a safe place unlike a rock which can be put anywhere without problem. Men are of neutral energy like a rock and doesn't have special needs and care.
But, women are of high energy and they should be handled with proper care and attention. If we put them in the position of a diksha guru, the kind of atmosphere it creates is difficult for most of the men to handle.
For instance, a man at workplace has to just do the work mechanically under a male boss and if it's a female boss he has to handle it differently. Men get confused if they are put under a female boss who has different needs.
References from Bhakti Vidyapurna Swami Maharaj class on she can't become a guru.
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Best Regards,
Dinesh