Philippa Cross examines the truths and untruths of ad agency staff turnover [1] for South Africa's Marketingweb, and guess what - Some crap is universal.
Everyone is replaceable
It is my hunch that, whether consciously or not, in the back of the mind of most managers is the belief that everyone is replaceable.
Furthermore, there's an attitude (perhaps subconsciously) among management that employees should be grateful for work at all, and should count themselves lucky to work for "this great advertising agency". If an employee doesn't want to accept the status quo of the agency, they can leave. "There are plenty more where you came from honey".
Links:
[1] http://www.marketingweb.co.za/marketingweb/view/marketingweb/en/page71639?oid=95228&sn=Marketingweb detail
[2] http://technorati.com/tag/advertising news