Anyway, here is my reply. Reading the original post will probably provide some necessary context to this.
hmmmm I remember wondering about this English/hindi gaali funda when I first came across english gaalis (at IIT I guess)... but since then I have had experiences that have illuminated the issue for me. I don't think the degree of offensiveness/obscenity of any word has a lot to do with the actual meaning. Probably only to the extent that these words started to be considered offensive/obscene because of the meaning but the degree is more often than not "learned" from your family/society. You realize it only when you come across a word that you have seemingly always considered highly offensive and then you come across another word that means exactly the same thing and yet doesn't offend you. Its amazing how quickly our reactions get correlated with just the way a word "sounds". I suspect that if someone does a study about the order of interpretation of a word's meaning by brain and the onset of the feeling of offense, it will be found that the latter probably precedes the former. Or at least that they are not necessarily correlated to a high degree.
There was a time when I uttered a particular word that didn't mean anything to me and ended up offending a Puerto Rican friend of mine because it was a highly offensive word in spanish. So much so that she visibly flinched every time I said the word and could not bring herself to say the word aloud even when she was actually explaining the meaning. Like I said, very often we just reflexively react to a lot of these sounds. If you wonder why "Maadar**od" is so much more offensive to hindi-speakers than "Motherf***er" is, consider why "T*tti" is considered a dirtier word that "Paikhana"... or "G**nd" dirtier than "Pichhwaada". The whole concept of a euphemism is based on the fact that we don't react to the meaning of a word but the word itself (which probably means the sound pattern).. and a corollary to that is that we tend to react more strongly to the words in the language we grow up with rather than an acquired language. No wonder you get to hear "Sh*t" much more often in IIT than in a US campus.