Putting aside the fat that the OP asked about standards....I'd just answer the questions before you start spreading propaganda !
The certification of the helmet is the only way that the consumer has to assess how effective that helmet is in an impact. It is an international market and Keith Oates above has a prime example, his helmet is CPSC certified and offers a higher proven impact tolerance
A Snell certified helmet is tested at a higher impact energy than EN1078 on a flat (2.2 m fall as opposed to 1.5 m) and kerbstone (1.2 m as opposed to 1m fall) anvil than EN1078, and also on a hemispheric anvil (1.3m) which EN1078 does not even test
CPSC, ANZI ASTM(now ANSI) in the US, Canadian and Australian standards all test at a higher impact than EN1078 and are proven by these tests to withstand a higher impact.
If you dismiss all these tests as propaganda, how do you suggest a consumer assesses the level of protection a helmet will offer in an impact
How do you assess which of two helmets can withstand a higher impact?