Wow. That just seems weird to me -- but I've only had two jobs in the last 16 years.

Both my mother and her father worked at the same place (a General Electric appliance factory) for most of their lives. My grandfather was there on day one and remained until he retired. My mother started there ~20 years after he did and was there until the day they shut down. I know of one man who worked there for 44 years!

Switching jobs every two years seems so foreign -- and somewhat "suspicious" -- to me.

"According to the survey, millennials who work in large, private-sector organisations have lost faith in the ethics of these organisations over the last year."

The last year? I think the rot set in during the Thatcher/Reagan era. Corporations showed they had no loyalty to their employees so they shouldn't be surprised when their employees respond accordingly.

Don't we normally strive to be above average?

Staying at a company a long time isn't intrinsically and self-evidently better. For instance, switching jobs every 2-3 years will both maximize your salary and allow you to diversify your equity compensation (for more irons in the fire) [1].

Staying at a job for a while is a means, not an ends, and as such not necessarily something to optimize for.

Myself having 0 felonies makes me below average (as 8% of Americans have at least 1 felony), and I don't see myself striving to be above average in this category ;)

[1] https://globalnews.ca/news/3946085/switching-jobs-pay-boost/

I'd certainly hesitate applying an average across a broad demographic to presumably well-paid and well-educated professionals in a technical field. As others have noted, if someone has a resume of 2 year stints for no particular reason, I assume that pattern will continue. If they bring something special, that may be fine. But I'll factor the likelihood they'll be gone in 24 months into my decision making.