Yes, I think it's possible to have sympathy for the loved ones of both victims. I will admit my sympathy for DS has been severely tested over time due to her treatment of the Zahau family and her documented history of domestic altercations. And I find it particularly difficult to muster sympathy for NR as a result of the interview in which she showed greater concern for lost yoga pants than for the loss of a human life. But I do believe losing a child is the greatest pain a person can possibly experience and in that sense I have a great deal of sympathy for DS, JS and Rebecca's parents.
I do not believe DS suspected Max was endangered in his home environment at Spreckels. According to NR, while Max was at Spreckels, DS felt comfortable enough to wear earplugs and retreat to a remote area of her home where she would not be disturbed by phone calls or the doorbell for several hours, regardless of circumstances. IMO, that suggests DS was confident Max was being cared for adequately at that time.
I also understand why anger would be directed at a caregiver in a situation in which a child is gravely injured. I think it's a natural response, in fact. And I think it's reasonable to expect caregivers to do what they can to minimize risk in a child's environment. But no amount of vigilance can prevent 100% of accidents. Additionally, most six year old children enjoy brief periods of unsupervised play and the expectation is not to have eyes directly on them at all times. That is not to say it would not be irresponsible to allow a child to play with a scooter at the top of a staircase, if a caregiver was aware of that behavior.
Oftentimes, accidents occur as a result of multiple risk factors coming together unexpectedly. One thing that perplexes me is that, in this case, while several factors may have conspired to create this tragic event, some of the most obvious are being ignored. For instance, the banister railing is reportedly too low. Why is that being ignored? If Max fell over the banister, is an inadequate banister height not as significant as the fact that he was unsupervised when he fell over the banister?
All of the above is just my opinion.