But they're not even popular in all of Germany! The "Weisswurstequator" - a rough dividing line north of which the white sausages just aren't a thing - also largely applies to soft pretzels.
https://en.wikipedia.org/wiki/Wei%C3%9Fwurst%C3%A4quator
Nutella also sounds like an abomination to me, though savoury toppings - butter, cold cuts, cheese - are OK. Though a fresh pretzel is such a treat you've usually eaten it before giving much thought to toppings.