Products & brands that sell a lot (successful) also end up on the used market a lot. It says far more about the nature of this hobby and its fickle hobbyists (that’s us), rather than being a damning statement about the product’s performance.
If the product was truly mediocre or defective, then you’d usually see the big market spike shortly after the initial hype, followed by very little activity at all. But then some very good products have also suffered that same pattern - again, it’s the nature of this hobby.
The VPI unipivot, at least since they refined the VTA tower, is fine. If anything, I have more problem with the 3D arm material they’ve switched to. It’s very excitable in bass frequencies. The later JMW series and Classic 3 metal arms are relatively underrated in their lineup, IMO. I guess people fixate on the HF ringing with metal - the bass issue is much more trickly, IMO.