The interviewers usually ask particularly inane questions when he's just come off court after a gruelling match. No wonder he doesn't seem enthused.
Do you really think some random BBC reporter manages to evade security and be there waiting in the corridor to the players' changing room every time?
Because if you do, I think you should be wondering about other security arrangements at the venue.
Players are obliged by the All England Lawn Tennis Club, who run the enormously profitable Wimbledon championships, to give a brief interview to the BBC after walking off court and then to attend a press conference with other journalists whether they like it or not.
I'm quite sure the reporters interviewing them, particularly when they've just walked off court, know that they are exhausted and their minds are elsewhere so they ask a few questions and let them go.
You might think they are inane, I don't, it's just the job, just like being a tennis player is a job. If you want to blame anyone for the set up, blame the AELTC who are in charge and insist on post match interviews as a service to sports journalism but also to keep interest in the most prestigious and profitable tennis event alive.