Would you find this respectful:
Those who reject (Truth), and follow Islam, will be in Hell-Fire, to dwell therein (for aye). They are the worst of creatures.
Would it be respectful if I called you and all other Muslims worse than pigs, rats and maggots ?
Allah says in the Quran:
Nor did those who were given the Scripture become divided until after there had come to them clear evidence.
And they were not commanded except to worship Allah , [being] sincere to Him in religion, inclining to truth, and to establish prayer and to give zakah. And that is the correct religion.
Indeed, they who disbelieved among the People of the Scripture and the polytheists will be in the fire of Hell, abiding eternally therein. Those are the worst of creatures. (Quran 98:4-6)
We don't call people names. Allah told his Prophet and the Muslims to be kind to others and be peaceful but in the eyes of God if someone reached to judgment day and ended up being in hell, and forever? then it means they are the worst ever since many who will enter hell can still go to paradise later on.
Anyone who is sincere in his search for the the truth he won't be of that level whether he is a Muslim or non-Muslim. The verse talks about those who intentionally disbelieve.
Nevertheless, it is childish to think of this verse as an insult like pigs and all sort of these things. Worst not in term of being human or non-human but worse in term of statues on the day of judgement. Don't forget that Allah himself is the one who created us and told us how perfect he created us as human beings.
He created the heavens and earth in truth and formed you and perfected your forms; and to Him is the [final] destination. (Quran 64:3)
I don't think anyone who fail to enter paradise will be anything but the worst since he/she missed entering paradise. Even in paradise itself there are many types of statues, there are the best and there are those who would barely make it, and those who are perfect in the highest statues, and so on.
Only you can choose your destiny, but in this life, i really won't bother to label anyone anything since i personally don't know whether i'll end up in heaven or hell.
So it's not for any human being to judge who is good and who is the worst.
I hope that answered your question, and Allah knows best.