I have to say I've not heard anyone suggest that they should be herded into gas chambers.
I have also not heard any valid reason as to why they should stay.
They knew when they arrived that they did not have permission to do so. I am amazed it has taken this long to get them evicted. I feel very sorry for the local residents and the travellers that are on the site legally - their name has been dragged through the mud with all of this and their reputation tarnished.
If I were to build something on my land without permission, I would rightfully be ordered to take it down. I'm struggling to see the difference