Who said that? What in the wide world of sports are you talking about? It seems to me that there is an expectation that everything in DISCO fits in to some mold that is not privied to everyone.Apparently not. In reading this thread it would seem that these guys be they hero or antihero have done everything without fault. Who would've thought, lol.
Starfleet had no reason to think the Shenzou had valuable intel. There is no indication that Starfleet protocol requires destruction of the ship. The battle left Starfleet licking its wounds and rebuilding, so pushing in to disputed territory would invite an attack they would not be prepared for.
tl:dr There is no precedent for Starfleet officers destroying their ship to prevent capture of technology by the enemy.