If you know what Rooh Afza is, water or milk?
You don't have to be Muslim
from what Ik outside India roohafza sharbat is quite popular especially in Pakistan and Middle East so my guess is they developed liking for the water variant of the drink and some might even be lactose intolerant but in India most love falooda/kulfi-falooda with rooh afza
for me personally falooda/kulfi-falooda is top3 milk shake favorites
but roohafza sharbat isnt even among top10 squash favorites as there are much much better tasting options