1. Parents lives have been temporarily turned upside down as almost all childcare disappears. Temporary is turning out to be a long time... but still.
2. Most companies are composed of people of all ages and stages of life which means there are lots of parents. Particularly when you consider management tends to be older and more likely to have had kids, it's not too surprising that management in most companies has looked at the outside world and said, "you know, we're all going to just have to do the best we can until this thing is over."
3. Parents naturally feel (1) stressed out and (2) guilty when they are having a hard time maintaining their old workload given the new and vastly different circumstances.
4. Some small minority of tech workers without kids have been unable to empathize with the situation and are publicly complaining about it.
Given that saying mean things online is practically America's past-time, and trying to fan the sparks to see if you can make a flame is how news companies make money... it's not really surprising to see a story like this portraying some kind of "backlash."