Juston Seyfert going around with a sentinel is no different than a guy dressed as Hitler attending a Holocaust survivors' reunion. He should realize that the thing he calls his friend/pet had been a symbol of fear, racism and genocide. Which also affects minorities in the real world. The main theme that made the X-Men popular with other cultures is that they are,if not the first, one of the first minority characters ever published. Off-course they are not the black, Asian, etc., minorities but they fulfill the role as they are few and different compared to the base-line human majority. As with any minority, they have been persecuted and/or terminated by the majority or the elite. In such an event symbols are made(sometimes unknowingly) to remind us of what happened, sometimes offensively. Blacks/Africans would have the KKK burning cross, the Jews would have the swastika and the mutants would have the Sentinels. A symbol of persecution and genocide throughout the mutant-kind, sentinels are responsible for the genocide in Genosha, death of all of Emma Frost's Hellions, and the attack on Utopia.
It might seem foolish/childish to hate on a fictional character like this but as I said before sentinels are much more. A symbol of genocide for cultures that has faced genocide. Fictional or not, sentinels represent humanity's nature to hate what is different and ultimately destroy them.