I've probably been guilty of my share of that... Trade show demos are usually about showcasing some new products not always using the best system for the space. Sound rooms inside trade show booths can be horrible sonic spaces, and systems are generally operated by marketing types, better at talking that setting up systems. The character of a small sound room will change dramatically between empty and when the meat puppets are packed in like sardines. So even if set up right ahead of time, things change.
For several years I worked a booth where I had separate acoustic space next to a larger sound room with a window between us like a studio control room. I had a split off the snake and could run open mics through a console and studio monitors in my space. Trust me the band sounded a lot better in my room than in the live room. In my judgement more because of the room/gear than the operators. while I ran much lower SPL. Sometimes the demo is just physically impossible to get right. For years at Frankfurt, I would try to demo a recording console using a split from a live stage inside a sound room. Since I was out in the hall I had strict SPL limits that affected my mix. The LF bleed from the live band playing several meters away required me to get the rest of the mix level up to sound even... The sound polizie kept dinging me to turn down the bass, and I'd have to show them how it didn't go away when I tuned my system completely off. I'm sure the majority that walked by without stopping, thought I had sh__ for ears and did a bass heavy mix on purpose.
Over the years I have experienced many operator errors from non-sound men running sound demos. Just because people work for a large equipment manufacturer does not automatically make them experts at operating that same equipment, even if their bosses think they should be.
This is no excuse and it does distract from the message.
JR