"Heavy criticism" refers to the act of strongly and negatively evaluating or disapproving of something or someone. It implies that the criticism is severe, harsh, or extensive. Full definition
The Conservatives have come under heavy criticism for the disability cuts, even from members of their own party. (mirror.co.uk)
The tenure reforms have drawn heavy criticism from educators who worry about the reliability and fairness of relying on standardized tests. (hechingerreport.org)
Insurance companies came under heavy criticism because they routinely searched death records to stop retirement and annuity benefits, but did not likewise conduct searches to determine if there were unpaid life insurance policies. (thelifeinsurancelawyer.com)