Referencing the 'second list' reported in Des H's latest post, I'm not surprised at the absence of Otto Klemperer's name as an 'influencer'.

Klemperer never intended to 'entertain' his audiences - he set out to challenge them. He was, as Lotte Klemperer confirmed, not interested in popularity. His interpretations were the opposite of generic and that's part of what made them so interesting, even if one occasionally disagreed with them.

He was one of a kind: attempting to imitate him would have been futile, being 'influenced' by him almost as difficult.

To me, that confirms him in the pantheon of great conductors, rather than excludes him.