Why Organisations don't bother to invest on Management personnel and never consider them key asset?

Organizations have learnt to do so and now employees (not only management) are considered assets and investments are being made to train and retain employees.

The organizations which are not in line with this philosophy are generally the ones which either do not expect to be going concerns or exist in the markets where they are in exploitative positions and employee turnover does not harm since there is vast pool of talented professionals readily available to be exploited.