Excuse me, hope? Evacuation was not necessary because there was hope that things weren't as bad as they have turned out to be?
And honestly, as someone who has heard a billion Russian jokes about "volunteers" in the USSR, every time you use that word is jarring to me. I'd share the anecdotes with you, but I suspect you already know most of them.
In this case we know for sure it was volonteers. First of all most of them are alive and USSR is long gone, so they'd already came up with their stories of forced participation. You just trying to diminish geunine heroism of people just because they lived in USSR.
The handling at Windscale was even worse. Even before the 1957 fire, the neighboring villages and countryside were getting contaminated daily without any authority doing anything about it.
But I think it's also well documented now that the Ukrainian communist local authorities could have handled the evacuation much better and much sooner. If only for having the tendency to wait for higher ranks from Moscow to take the difficult decisions for them.
Emergency works on station began immediatly, specialists from Moscow were there in the early morning. There was no immediate need of evacuation at first according to dosimetry and prelimenary damage assessment. It took some time to realise the scale of destruction to the core zone and that triggered evacuation.
Moreover if you compare it to Three Mile Island incident this was done faste and was organized better.
It's not about patriotism. Similary to volonteers during COVID outbreak people knew the danger but felt that they need to do something to prevent graver harm to society and people. Please note that we're talking about 1980s and Soviet people were properly informed about radiation and its effects.