Ah, I see we're once again whining about aspects of the show that the creators specifically mentioned in the lead-up to its release. These are supposed to be more nascent orcs, who haven't had the thousands of years of battles to toughen them up in the same way that "modern" orcs in the LotR era are. It's why they're relatively pale, wear light clothes, and don't have chunks of metal bolted everywhere on their bodies.
And this is all seemingly ignoring the Uruk-hai...who were notable in part because of their ability to move in the sunlight without issue. Whether that's because it would physically injure regular orcs, of if it was more a psychological thing is basically irrelevant.
But it is funny that you keep bringing up vampires, as if there aren't myriad interpretations of those, and the different things that weaken and/or kill them.