Number of Reasons for declined to PIL is as follows –
A_) The Court has to rely upon the report of commissioner, which are likely to be manipulated and hence no clear and true aspect of the thing possible.
B_) The Court has no independent investigation machinery to find out correct picture of the case.
C_) The court has no effective machinery to enforce its order and moreover such orders are against the government and administrative authority and not against the individual.
D_) The Government has limited resources and numbers of needs to be fulfill. This resources are to be utilize for the planned development of the country , Government has its own problems and the orders of the court cannot be given fully effect of i.e Olga Tellis Case of pavement dwellers of Bombay .
E_) It is difficult to find out whether the petitioner is privately or politically motivated.
F_) Because of judicial activism numbers of PIL Petition were being filed before the court and the court concentrated on them, thereby wasting of lot of time and energy on them ignoring their traditional function resulting into more pendency of ordinary litigations before it.
G_) For vexatious baseless petition no penalty, hence the parliament of India intending to take proper and adequate amount by way of security towards PIL to avoid multiplicity of PIL to give relief In proper cases.