It’s completely silly to think that the way we dress doesn’t affect the way we feel. Completely silly. The way we feel, more or less is our consciousness. So its completely silly to think that how we dress doesn’t affect our consciousness.
So, if we want to develop divine love, its helpful for us to dress in a way that makes us feel like we are divine lovers. Young unmarried boys and girls do their hair, take care of their faces, work on their curves and bumps, and dress up because they want to attract a mate. The way they look (a) affects how attractive they feel, and (b) affects how potential mates feel about them. Similarly, if we want to attract bhakti into our hearts – why would we think that the way we dress, etc. has no bearing whatsoever on that endeavor?
I think, to be perfectly honest, we think it doesn’t matter how we dress because we aren’t really that interested in attracting our soul-mate.
For Gaudiya-Vaiṣṇavas, there really isn’t a book more śāstric and authoritative on the subject of how to attract our soul-mate than the Bhakti Rasāmṛta Sindhu of Śrī Rūpa Goswāmī. He mentions the importance of external appearance by including it as one of the 64 limbs of sādhana bhakti. In other words, Śrī Rūpa says that keeping a devotional external appearance is not just “important” its an actual limb of sādhana, its a way, in and of itself, of cultivating bhakti!
He lists it as the 21st practice of sādhana: vaiṣṇava cihṇa dhṛtiḥ – which literally means “bear the marks/ insignias/ signs/ brands/ symbols of a Vaiṣṇava.”
This doesn’t mean that we have to dress exactly as encoded and endorsed by whatever the current version of the currently authorized Bhaka Handbook currently distributed by the current government of the current International Krishna Movement. But it does mean, quite simply, that we should adorn ourselves with symbols, clothing, marks and so on that are indicative of devotion to Krishna.
In other words, it doesn’t have to be a sikha, or an official “mātājī” braid, or a kurta and properly “tailed” dhoti, or a sari etc. etc. etc. but it does have to be something. We have to dress and make our appearance in such a way that it reminds us of Krishna bhakti. Whatever that happens to be for you, go for it.
Arguing with simple and obvious things like this doesn’t really portend well.