This is something I’ve noticed lately. A lot of hifi shops and hifi manufacturers have helpful staff, but just as many are extremely rude and arrogant.
I’ve had people speak condescendingly about my amp when I’m demoing speakers. Same thing for my speakers. I’ve even had someone, and I kid you not, tell me my streamer has shit sound quality.
It seems like hifi shops are either extremely helpful or just downright awful. The same with manufacturers, they either recognise that there exists alternatives or everything sucks ass compared to their product.
Maybe your equipment is substandard in some respects. But there is no reason to be nasty about it. Everyone is entitled to their opinion, and different people value different aspects of sound reproduction.
When potential customers are treated rudely, it doesn’t serve anyone’s interest. Work with companies and dealers that treat you right. Screw the others.