Jesus washed only His disciples feet at the first Holy Thursday. Francis washes the feet of disciples and non-disciples when commemorating Holy Thursday. 

So either Francis is right to go beyond doing what Christ did (and Christ didn't get it completely right by not getting down on His knees to wash the feet of those who didn't believe in Him), or he is wrong to depart from the example Christ left at His Last Supper and do his own thing. 

Which is it?