Earlier quoted context omitted.
The reason simply is late stage capitalism, there's not enough upside anymore, so why bother do a good job? That's how I explain it. I noticed that as well with almost all employees, there was a shift. And it feels like it's got to do with misaligned incentives. Why bother working yourself stupid if you'll never own a house if you don't become a slave to the loan? There's no upwards movement/middle class anymore.
I don't want to put quite that fine a point on it, but generally I agree. I think people see that wages have been stagnant for a long time and spending power has gone down. Working harder gives them marginal, if any, life improvement. I'm reminded of the Lithuanian immigrant character Jurgis Rudkus from Upton Sinclair's "The Jungle", whose response to continual setbacks was "I will work harder", only to ultimately be…
Granted, the horse got shipped off to become glue, rather than ground down by life, but the effects are pretty much the same.