The report states that the first officer "found the captain slumped over the controls" which very much implies he'd bypassed the crew room and they hadn't met up to that point. It's hardly likely he saw him obviously drunk but waited until he was on board to raise the issue! The100% crew room screening some are demanding would be hugely intrusive and expensive. And crucially would have made no difference in this case. But if we really do feel it's necessary, why start with pilots? Medical profession would be first on the list, professional (or maybe all) drivers, nuclear plant personnel, armed police.....