Banning working from home was still the wrong move. It showed that they weren't assessing people on performance. If they were, they'd have simply fired those

Banning working from home was still the wrong move. It showed that they weren't assessing people on performance. If they were, they'd have simply fired those folks who were underperforming (and as you point out, spoken to their managers as well.) Banning working from home without realizing also the probable PR/culture cost is yet another mistake.