If this statue is on a piece of publicly owned land it could be that it's against the US secular constitution to put it there, I'm not certain but this sounds like it to me.
Can't remember the details but there was some sort of case where someone or a group wanted a statue of a religious figure of some kind or a religious dedication placed in the foyer of one of their courthouses; it was taken to court, not a pun, and it had to be removed in accordance with their secular constitution. That case wouldn't have been any more than about five years ago.(I'll have a look and see if I can find the details; the above is all I can call to mind at the moment).
If that's all it is this non-religious group just didn't like the statue, I would side with Vlad; but I think it was more than likely something to do with with an infraction of their secular constitution that made them want it removed, in which case it's a perfectly legitimate principle that should be upheld.
ippy
PS, found it the info about The US secular constitution; one of the relevant cases.
http://www.secularism.org.uk/blog/2013/07/a-right-for-one-is-a-right-for-all