"Not reflective of how music was performed in Bach's day" is a data point, not a judgment of quality of an interpretation. If "molto rubato" is a complaint it n

"Not reflective of how music was performed in Bach's day" is a data point, not a judgment of quality of an interpretation. If "molto rubato" is a complaint it needs to be followed by an actual criticism. For example-- I remember someone (Kissin?) using "unsuitable" rubato in one of Brahms Paginini Variations. The problem was that it obscured the 2-against-3 texture in that variation. By applying rubato the entire time, that rhythmic drive never gets established and the variation seems less effective for it. (And rhythmic drive is very often central to Brahms' music.) There are costs and there are benefits to any interpretive approach. But I'd be very cautious about going down the "modern lens" rabbit hole. At least for the 20th century, Taruskin persuasively argued that the "authenticity" movement mainly ended up reproducing modernist interpretations of Baroque and Classical period music.