This is a very cultural thing. For example, in Germany it is frowned upon to switch companies too often. If your CV shows that you switch jobs every few years, this is considered a red flag since this candidate will not be very loyal to your company.
I also ask myself whether the "company incentive structure" is the cause of switching jobs; if it is easier to get more pay by switching companies than by staying, then of course candidates will be prone to switch. So perhaps not what is broken (in terms of loyality) is "eng hiring", but the incentive structure of the companies that want to retain the engineers.
