Back to what originally prompted this thread...catering for vegetarians....
....I believe that anyone cooking for anyone else has to be sensitive to their preferences and needs........IF they want them to enjoy their meal (a big IF, for some, perhaps?). It seems to me that it's simply common courtesy that comes with being "a host"...and I think it applies to ANY cooking, not just curries.
Regarding curries, even within the family context, if I cook one, solely for myself, I cook a stinky hot one (e.g. a vindaloo or phal). But my wife doesn't like them as hot as me, so I generally cook milder curries (e.g. madras, jalfrezi, etc) for her. I then "spice" them up for myself. Our children prefer even milder curries (e.g. CTM and Korma) so I often cook these, if they are having some.
My wife doesn't eat red meat, so I generally make chicken or prawn curries. I prefer red meat (e.g. lamb), so I occasionally cook a stinky hot lamb curry just for me (yes, selfish, I know).
We have friends that like red meat but not lamb, so, if we're entertaining, I don't cook lamb for them. We have Muslim friends, so I don't cook pork for them. We have friends that prefer vegetables, so I cook vegetables for them. We have friends that aren't too keen on coloured (or pilau, or fried) rice, so I also make plain, uncoloured rice. We have friends that love onion bhajis, so I make those for them...etc, etc.
If we're entertaining, I try to cater for everyone's tastes by providing a variety of dishes that I know they will enjoy (at least one or two or the dishes, if not all of them).
Is this a faff? Perhaps, but not for me. I derive satisfaction from knowing that they have enjoyed their meal to the fullest. And to achieve this I try to cater for their needs.
I reckon it's probably called being a good and considerate host?