Pianists certainly did things differently in the old days.The score was a suggestion or simply an idea.Arensky is certainly right about the Liszt pupils. You should hear Rosenthal play Chopin.I wonder what a judge in a modern competition would think of him???
I had a thought. Becuase they were still living in the time of composer/pianists (or perhaps just after) from the romantic era, perhaps the style of composition made it's way into their playing. I think I mean rubato more than anything- Extensive rubato which we don't generally use in the classical repertoire. I don't know if this is true, but it makes sense (I hope).
They'd hate him and I think that reflects negatively on the judging criteria rather than Rosenthal. His Chopin mazurkas are amongst the very best I've heard. His playing is certainly preferable to the banal performances one can hear at any international piano competition.