Obasanjo stated this on Wednesday, November 23 while speaking at the first Akintola Williams Annual Lecture in Lagos.
He said it is uncharitable for Buhari’s administration needs to evolve policies that will take Nigeria out of the current economic recession.
He said: "The blanket adverse comments or castigation of all democratic administrations from 1999 by the present administration is uncharitable, fussy and uninstructive.
"Politics apart, I strongly believe that there is a distinction between the three previous administrations that it would be unfair to lump them all together. I understand President Buhari’s frustration on the state of the economy inherited by him. It was the same reason and situation that brought about the cry for change, otherwise, there would be no need for change if it was all nice and rosy.
"No administration can or should be comfortable with the excruciating pain of debilitating and crushing economy. Businesses are closing, jobs are being lost and people are suffering.
"I know that President Buhari has always expressed concern for the plight of the common people but that concern must be translated to workable and result-oriented socio-economic policy and programme that will turn the economy around at the shortest time possible.
"We cannot continue to do the same thing and expect things to change."
The former president also criticised Buhari's plans to take about $30 billion loan.
He said: "I am sure that such a comprehensive policy and programme (that will move Nigeria forward) will not support borrowing US$30 billion in less than three years. It will give us the short-, medium- and long-term picture.
"Adhocry is not the answer but cold, hard headed planning that evinces confidence and trust is the answer. Economy neither obeys orders nor does it work according to wishes. It must be worked upon with all factors considered and most stakeholders involved.
"The investors, domestic and foreign, are no fools and they know what is going on with the management of the economy including the foreign exchange and they are not amused. The Central Bank must be restored to its independence and integrity. We must be careful and watchful of the danger of shortermism.
"Short-term may be the enemy of medium- and long-term. We must also make allowance for the lessons that most of us in democratic dispensation have learned and which the present administration seems to be just learning."
Obasanjo also criticised the National Assembly and the Nigerian military, saying it needs to be purged.