Based on EXTENSIVE (lifetime) experience with snow / ice, there is not a single vehicle of any make / model that doesn't have buildup like this. My 2012 Sierra had it, our Toyota RAV4 has it, and every Tesla I saw was exactly the same thing. In Canada it's called Winter and under the right conditions there's not a darn thing you can do about it. Temps down to -34 here last week and my wheel wells were plugged with solid packed snow every day and so was everyone's. The parking lots get littered with big chunks that people kick off when they are stopped and I'm sure I saw some that weighed 15 pounds off of bigger trucks. They even hang below the mudflaps and build up behind that on the running boards. My 2012 would sometimes have so much buildup (no mud flaps) that opening the door was a problem with a dirty snow cone reaching the lower corner of the door.
I don't think we can blame GM for any of this is my point. Blame Al Gore for being wrong about snow not existing after 2010.