As an airline pilot myself (former delta connection), the non-rev benefit is something that is great when it works, but an absolute nightmare when it doesn't. Over the last few years I've non-revved domestically and internationally. Domestically 80% of the time I was in Y, 15% in C+, and 5% F. There were however countless times I'd come nowhere close to clearing the standby list. As a DL connection pilot we were below DL mainline employee (both active and retired) so it could be very tricky. Internationally I always cleared to C+, but never made the cut to D1.
I'm still a pilot, but for a non DL affiliated carrier. So my priority is even lower than a DL buddy pass. I don't even attempt it anymore. Too much hassle. I'm back to buying confirmed tickets (Y and the occasional F) to gain status, miles, and overall avoid the headache.
I believe it is correct airline employees should receive these benefits, but I also believe they should drastically limit the benefit to a certain number of segments per year. It's to the point that many airline employees (myself included) can't enjoy this perk of the job because of the dozens and dozens of non revs that list for each flight.