Part of the issue is that these oils are no longer licensed as SE, SF, or SG. No one polices it, and no one can really claim they are SE, SF, or SG licensed, unless the stock is dreadfully old. So, unless it's a company that you trust and they're actually stating it's made to those standards, and they aren't skimping on the additives and are actually trying to make a high phosphorus, high HTHS oil, I'd steer clear.
Any you always have to be wary about what you're getting, even with a trusted oil, if you're going for a motorcycle application. Some non-certified oils from the majors (i.e. racing oils, VR-1 comes to mind) specifically warn against using them in shared sump applications, due to a good dose of friction modifiers.