I attended Thangool fly-in last year - expected their appearance and sure enough they were there doing their thing. I didn't speak to them or hear of any problems, but certainly a disincentive to attend these events. It is like a show of strength and we don't trust you clowns.
We all know you are liable to a ramp check at any time, and I have no problem with that, but to attend somewhere where you know (or expect) the inconvenience to be occurring must have some negative result.
I have operated out of class C (by different names) since my student days and have never had the displeasure but to expect ramp checks at every fly-in is over the top, at least to my way of thinking.
One could be forgiven for believing it is more about getting travelling allowance expenses then "safety".