Not sure, whose what body cavity that 98% figure came from, but as you said yourself there are issues with the music player that affects not just those who listen to USB music. Let's try to agree that people listen to different music sources based on their needs and we should all be able to reliably listen to music in the car whether it is USB, streaming, or Bluetooth rather than the mentality "I'm not affected so I don't understand what the problem is."
To be fair, I think the point was more “this is why I think it’s not a priority for Tesla” vs “you shouldn’t be complaining about this”. They have limited resources, so have to focus on features that drive sales.
While I can understand frustration from, say, a fart app being released while USB music player functionality is broken, the fact is that said fart app was a wildly successful marketing move, where adding USB support would please some small number of existing owners and then fade away.
At some point, obviously, that minority becomes more vocal and the problem needs to be solved to prevent loss
of sales from bad word of mouth(and lack of repeat buyers). Hopefully, with them already touching the music app a lot for v10, now will be the time they get to it, but I think the above is the reason they haven’t so far.