I have been peed off to see children being sick en route to school and their parent still taking them in, my children have had d&v over and over due to this sort of thing.
Ive worked in a nursery when a child will come in at 8am and by 10:30ish they start to flag, they have clearly been dosed up on calpol and sent in, its not nice for them and of course means other children and staff get ill too.
While all of that stuff pisses me off, im also a single parent and understand the pressures, what can they do if they have to go to work and have no one else to care for their child, also if you have more than one child the illness usually does the rounds so that multiplies time off by 2-3x.
I know that does apply to couples to but at least in a couple you can spread the time off between the two of you.
Sometimes parents are damned if they do, damned if they dont.