A finisher in Dallas told me my doors were fine but my setup was garbage

I had a finisher walk through my shop in Dallas about 6 months ago and he barely looked at my doors. He ran his hand along my assembly table, pushed it, and said "this thing moves a quarter inch and you're blaming the wood." I had been fighting inconsistent reveals on my shaker doors for months, and I kept tweaking my cope and stick setup. Turns out my bench had a 3/8 inch sag in the middle from years of clamping heavy stuff on it. I bolted a straight 2x4 under it and shimmed it level, then built a flat torsion box top for $60 in plywood. My gaps went from plus or minus 1/32 to dead on, and I stopped wasting material on redo doors. Has anyone else had a tool problem that you kept blaming on your technique?