They say that because they're fully indoctrinated, they drank the "mental koolaid" no matter how much new light and flip flops the borg puts out, they just eat it up without thought. Just like the folks who turn out for Trump's rallies, whatever he says, they just eat it up.
Like I said a few weeks ago here, if Trump and the Borg said that from now on 2+2=5, they would totally believe it.