I think it could be handled better, but how......
There are WOH parents who will do everything in their power to get their child to school each day as their employers are relying on them and will take a dim view of them 'phoning in the morning (short notice) requiring a day off. Illness has to be fairly bad (not manageable with calpol) for them to keep the child off sick.
There are other parents who have less stress over a child being a little below par/under the weather as they are SAHP who can re-arrange their days activities to accommodate a day at home for the child in question.
These are 2 extreme examples of possible parent types but you can see how one's view of a cough/sniffle/slight temperature might differ to the others.
Perhaps there could be half termly league tables with competition between local partnered schools with a prize to fund a piece of play equipment/extra computers to incentivise parents. Something achievable with just a little extra effort in not having days off unless absolutely necessary. Parent peer pressure just might then come in to play if X school got a new outdoor climbing frame because they won the attendance league this term and Y school parents really wanted the same for their school.
As I see it the only room for improvement would be guilt tripping parents who either
a) keep their child off for very minor health reasons, or
b) use "illness" as a cover for a duvet day at home with their dc (This really happens, I know of 2 parents who do it a couple of times a year) or
c)take their kids out of school to visit a theme park type place in term time as "you'd be mad to go in the school holidays or at a weekend, the queues are horrendous !", or
d)take their kids out of school for family get togethers like weddings/funerals etc. (Personally I suggest one guilt-free day a year amnesty which parents can use at any time for a funeral/wedding etc. Incidences of both must be fairly standard across the population).