why was public sector given more importance then private

Dear student, 
The public sector was accorded a greater role than the private sector during the five year plans. The following are the reasons for the same:
 

• Need for heavy investment: For the industrial development heavy investment was required. However, it was correctly assumed that the private sector would not be able to make such huge investment and take up the risk. Moreover, the investment in the industrial sector had large gestational periods which the private sector would not be willing to take up. 
• Low demand: Due to widespread poverty and low level of income the demand was also low. Accordingly, impetus required for the investment by the private sector was lacking. So, there was a vicious circle of low investment and demand The demand could only be encouraged by the public sector.