What is the rationale for the grant to the President of the privilege of immunity from suit?

The rationale for the grant to the President of the privilege of immunity from suit is to assure the exercise of Presidential duties and functions free from any hindrance or distraction, considering that being the Chief Executive of the Government is a job that, aside from requiring all of the office holder's time, also demands undivided attention. (Beltran vs. Makasiar, G.R. No. 82585 November 14, 1988)