Not every punter can watch races live and some find out later that a race of interest was Abandoned
such as R2 at Ararat last night (due to a driverless horse causing trouble in the field)
But there is no replay available and rarely are you going to find an explanation anywhere until the Stewards Report comes out (which many are not going to read or maybe even know how to access)
Shouldn't those who invested money in a race be able to see/obtain an explanation

A somewhat lesser reason is also when some of the field continue to finish the race - that becomes their most current form and shouldn't punters know about it