Does "darum" work here
Darum, deshalb, and deswegen are three synonymous adverbs. They can be used interchangeably.
Would a German every say "Das ist warum" or would that sound clunky?
I used it in Deutschland and they understood me just fine.
Why can't 'deshalb essen wir nichts' also be correct?
"Essen" is "to eat", "sehen" is "to see". This sentence is looking for "see".
Seems like a pretty good reason why it didn't work for him.