In an airline flying a fleet of 320+ 737-800 aeroplanes into little and large airports across Europe, the average FO probably has <2000 hours flight time (turnover and command at 3000 hours being the norm).
I can perfectly understand why such an airline specified all its aeroplanes with only 1 tiller!
More than likely only because guys from Seattle charge big bucks to fit it on 737. Same reason why they don't have fail operational aircraft, even though it's an option since 2003 I believe.