Everyone knew the risks. And if the didn't by December and could t find the statistics for themselves by December then they should have had family looking out for them. (Thinking those with LD etc).
Boris never actually said it's safe iirc. (And he's said some absolute bollocks through this!)
We've had the same though at school. Parents who say well send children back when Boris says it's safe. They genuinely have no idea or concept that schools are everything we as a nation are banned from doing by law. They genuinely think that as Boris has said it's safe no one will catch covid there 
People can and should make personal risk assessments. I'm not suggesting they make them to ignore all the guidance but they can use local data to risk assess.
A prime example for me is I didn't go to shops like B and M or the range despite being open in January when our case numbers were 700/100k. I could see the risk of catching it was high when out and about unnecessarily.
I do use these stores and gardens centres now - and I'll be honest it's often for a browse for items I plan to buy - because we have a case rate of 16/100k and have done for 2 weeks now. All but 3 areas in a 5 mile radius of me have less than 3 cases reported and are white on the map.
I now also LFT twice weekly and not once.
I follow guidelines and don't break them. It's actually part of our school RA we are expected to. But I also use personal thought as to what is worth it within what I can do.