As has been covered music is a personal thing. Some like it to rev themselves up, others use it to calm their nerves. Others (like myself) like to absorb the atmosphere and use that to bring out their best.
In the case of Wimbledon, a large part of the aura of the tournament is the tradition. If the organisers are concerned that listening to music on the course is ‘disrespectful’ then they need to write the rules accordingly. If there is no rule then the athletes are forced to do what helps them the most and if that is to listen to music then so be it.
Personally my reaction to the comment is ‘To whom is it being disrespectful to?’. Other players? The crowd? The Queen? Surely not allowing athletes to compete at their best is also disrespectful?