One would argue this production IS the art of stagecraft. It's making a world out of common objects. It's what the theatre has been about since Ancient Greece.
I don't see minimalist productions being disrespectful to Sondheim... Hell, he is REGULARLY honored. Sweeney Todd is getting its second Philharmonic concert in recent memory. Company was done there a couple of years ago. He's been represented at Encores twice in three seasons.
If anything, these productions show that Sondheim's work holds up no matter the number of instruments.
Sure, no one does Rogers and Hammerstein with such minimalism... but their work also no longer appears with the regularity of Sondheim's.
"...everyone finally shut up, and the audience could enjoy the beginning of the Anatevka Pogram in peace."