Uzumaki sealing techniques probably weren't combative or powerful in the sense of fighting which would explain why they got killed. Had they been combative about their power and anticipated invasions they would have survived. I believe that the Uzumaki weren't as powerful as they seemed, and were killed out of an irrational fear from the other villages.
The Uchiha and Senju survived despite being clans without a village, and they were more than likely nomadic to avoid invasions of their settlements. The Uzumaki had a village, and should have been able to detect invaders and easily dispatch them. The Uzumaki weren't that strong, it's just the facts.
Unlike the Hyuga, I doubt the Uzumaki used their seals for devious or war-like means which would explain their easily avoidable demise.