Read an article some time ago, written by an American automotive design consultant. He related the time he was working with engineers from Mercedes. He said he really had to work to convince them that the cup holders needed to be bigger and more plentiful.
Yes, this was (or is?) an issue. When I started to drive cars (at the end of the 80ies) I always wondered why I could not use these tiny cup holders, e.g. for a normal bootle of water. I think they were designed when the only thing you could buy at a gas station were this tiny white little thin plastic coffee cups, which were so hot that you could only hold them at the top of the cup.
I see this whole situation as irrefutable evidence we need to scrap ETOPS and go back to trijets and quad jets. We'd NEVER have to divert if we only lost 1 out of 3 or 1 out of 4 engines..
Airbus is so desperate that they cannot find a solution for this new problem with the cup holders, that they are now considering to stop production of the A350 and re-start promoting the A380. „4 engines 4 more coffee 4 the pilots“