Moaning is one of the pleasures of retirement. I can speak my mind without fear of being sacked. So many workplaces perform sub-optimally, sometimes very badly so, because those that actually do the work and see the problems are too much in fear of their jobs if they complain to their bosses...who are often the people that caused the problems in the first place.
So moaning is good - we're telling it straight, telling it how we we see it, without concealment or dilution. We are free to tell the painful truth.