Much has to do with how a particular person/worker is treated by his immediate manager/TL/supervisor.
IT companies should consider this on priority and must keep a closer track to avoid hostile environment in office. Company policies are to be modified keeping general employee welfare not only the managers and consultants.
New Talents will stay if and only if they are given a fair chance to grow. And with 'grow' I indicate personal and professional satisfaction,well treatment, recognition of good work and not undermined at all.