Well, yes it is, since it doesn't have an infinite half-life and doesn't move around by itself. You're certainly not going to find it used in Montana wheatfields, yet CCD has affected bees here as well... so now what to blame?? Indeed, most of our acreage is never treated with anything, being non-arable grazing land or wilderness. Hasn't helped bees any.
I'd guess in addition to the viral and fungal agents that when they occur together have been determined as CCD causes already, there might be a genetic susceptibility in some lines of bees, but far as I know that hasn't been looked at yet.
I'm reminded that many a time, some OMG-Death-Chemical reaction has proven to in fact be due to a genetic defect. Frex, see MDR1 (multi-drug resistance gene) in dogs. Nope, it wasn't ivermectin causing illness and death; it was a genetic defect.