Why should I let that bother me?  Remember what Our Lord said:

"Blessed are you when they insult you and persecute you and utter every kind of evil against you [falsely] because of me. Rejoice and be glad, for your reward will be great in heaven.h Thus they persecuted the prophets who were before you."

Some of it is honest disagreement. Like the Orthodox believing we schismed from them. Why should I be bothered if they believe that in good faith?  Nobody believes the Lutherans lack apostolic succession and valid Eucharist and thus are ecclesial communities out of malice but theological disagreement.