"Us" is the object, the subject is "we". In Hungarian you do not say "nem minket...". I reckon in everyday speaking nearly everybody would say"us", but I wouldn't, and "we" should be accepted too. After all, it is the only correct answer, from a strictly grammatical point of view.
That's a very strict view on grammar you have there :D but true "we" should be accepted too.
That's not fair. I said I know 99% would say "us", and I am by no means saying it is not acceptable. I just say that not accepting "we" is unacceptable.
------- remember, grammar is how people speak, not the ten commandments sent down by the grammar police. it doesn't oblige anybody to speak that way.
"it is not WE" is not the way modern (for the last fifty/sixty years, anyway ) americans say anything similar: it is he, it is they... and yet if you put a "who" after the we/they/i/he/she, it's quite comfortable to say: it is i who did that, it is he who ran, it is she who yelled, it is we who cried, it is they who sang . although you'll still hear it is me who ... oh well . . .
Big 7 jun 18