I think a quick way to solve this is take to find a large percentages of powerlifters/weightlifters/bodybuilders who are have this kidney failure.
(Data are for the U.S.)
Number of noninstitutionalized adults with diagnosed kidney disease: 3.9 million
Percent of noninstitutionalized adults with diagnosed kidney disease: 1.7%
Source: Summary Health Statistics for U.S. Adults: National Health Interview Survey, 2010, tables 7, 8 [PDF - 1.3 MB]
Number of deaths from nephritis, nephrotic syndrome, and nephrosis: 48,935
Deaths per 100,000 population: 15.9
Cause of death rank: 9
Source: Deaths: Final Data for 2009, tables 9, 10, 11 [PDF - 2.1 MB]
Diagnosed and undiagnosed diabetes among people aged 20 years or older, United States, 2010
Age 20 years or older: 25.6 million, or 11.3% of all people in this age group, have diabetes.
Age 65 years or older: 10.9 million, or 26.9% of all people in this age group, have diabetes.
Men: 13.0 million, or 11.8% of all men aged 20 years or older, have diabetes.
Women: 12.6 million, or 10.8% of all women aged 20 years or older, have diabetes.
Non-Hispanic whites: 15.7 million, or 10.2% of all non-Hispanic whites aged 20 years or older, have diabetes.
Non-Hispanic blacks: 4.9 million, or 18.7% of all non-Hispanic blacks aged 20 years or older, have diabetes.
Total: 25.8 million people, or 8.3% of the U.S. population, have diabetes.
Diagnosed: 18.8 million people
Undiagnosed: 7.0 million people
7th leading cause of death (based on diabetes deaths alone not counting contributing conditions such as CVD and hypertension, stroke)
High protein is not a problem in people with healthy organs. Perhaps they can tackle the larger issues before running to demonize proteins.